I thought the infamous Zenith fault was the "critical safety capacitor". It was a 4-legged snubber cap across the HOT, 2 legs on each side of the cap, with B+ run through it. The idea was if the cap opened, it would kill the flyback's B+ supply and shut down the set. Problem was, the caps didn't fail open, they simply changed in value and caused the EHT to go up to over 50kV, arcing the neck right off the CRT and starting a fire.
One of the most common problems with electronics, cold solder joints. I've repaired many things just by touching up cold solder joints. I fixed my Ghetto Blaster boombox from the 80s which had weak audio output, it was simply not getting enough power. I guess the heat from the soldering iron woke up the main power filter cap.
Philips (EU) tv's had a similar recall early nineties after several tv's had burst into flame, and those were otherwise overengineered top of the line models that were produced in local factories still with overall excellent build quality, similar to the heydays of zenith. They had several vertically mounted boards where heat cycling and gravity killed the solder joints. I remember calling in the tv shop as a nosy kid after discovering the recall from a newspaper. That tv ended up having many, many hours of service without any other service until the tube was so dead all the colors started bleeding. Ended up swapping out the tube and giving it to a local charity where it was used for who knows how many more years. It also definitely was a thing in those days to whack your older television because of the bad solder joints.
And a bit earlier, GE had double sided board problems due to griplets having a bad solder connection due to differential expansion. We'd hard wire the circuits that had griplet connection failures to avoid recalls. I remember one that drove me around the bend figuring out a griplet related issue that was unusual. I fixed it after much effort and literally sleepwalking to the basement shop, to awaken that morning to find it repaired and some notes that made no sense at all. Yeah, I fixed the damned thing in my sleep. Then, there was the RCA with an MOV failure, it let go fully as I was looking directly at it. Thankfully, I yanked the cord before it could burn the customer's hardwood floor. And a Philco TV with an SCR horizontal output that had a similar problem to this set, the arc leaving me with a tiny blind spot to this very day... I eventually became the guy other shops called when they couldn't figure out what the problem was.
Funny, that failure is pretty much the same that got me my first TV in the early 90s. The one I got had an electrolytic capacitor with some other stuff in parallel to that big film cap. The film cap wiggled loose but it was by all means not visible. It made the electrolytic go boom eventually and the technicians could not figure it out. So it went to the bin when I got it. I did the same, replaced the electrolytic cap, and after a day - it popped. Reverted to "bombarding" everything with solder and then discovered that the film cap was actually loose. After that fix I used that TV until 2006 before I got a flat screen.
I remember an old RCA with a color problem. Eventually, I didn't have the time to play with it, so I sent it to a local RETS electronics school for repair - which they never managed to fix. So, one holiday weekend after getting it back, I found a fractured solder joint on the delay line. Needless to say, that was back before my arms started getting shorter... ;)
I remember walking home from school in 3rd grade and seeing my neighbor's 1964 RCA (CTC-16, probably) roundie color set out in the driveway with holes burnt through the area around the tuners. Their daughter had been watching Romper Room when it burst into flames; I've since heard that it was the thermistors that RCA used, to delay the power-up while the tubes were warming up, that caused such fires. Some sets from that era (Admiral & some others) were also known for fires that spread when wax dribbled out of the flyback. I worked on Zenith monitors from Mexico in the '80s and never saw such junk; those plants were going through labor conflicts and it showed in the lack of workmanship. I still have a 1988 GE stereo set (CTC-136) that had a similar problem to this, but it was a special capacitor in that area that looked like a ceramic disc, but was made of plastic and cost a lot more. It filled the room with smoke, but that was just the fusible line-dropping resistor doing its job. I replaced the cap with a ceramic one and the set has been fine ever since.
Stay tuned. I have a vintage radio from the late 20's to go up, and another vintage technology digital clock build that uses 6 VFD tubes. Been waiting months for a package from Japan, and it finally arrived.
There are guys in the retrogaming scene that are trying to make an RGB input for these old tubes, so they can get the most out of the tube and the console. In this case, there is no sound input, but I'm guessing that if you can get an RGB input signal working, you can also get an audio signal in. That's a nice project (and tutorial), that will also give new value to these old TV's with no inputs other than RF.
The problem here is safety. These are AC line operated sets, and thus have a hot ground. That would be a major safety problem connecting anything to this or any other set like this. You would need to design an opto isolator. I should drag out my old Sony KV1965 and I can go though how sony put a video in on a hot chassis. They did it with optical isolation. Other companies did it with little transformers on the old sets. Then they went to switching power supplies to isolate the AV portion of the chassis from AC line. This one has neither so the only safe way to use this set as a monitor is to use an RF modulator, or plug the set into an isolation transformer.
I've found that if any of these sets were abused by poor handling as one might expect these connections would easily fail. A good number were all abused and dropped on the floor situations causing multiple damaged circuits that are really beyond any reliable repair.
Your videos are inspirational and motivational ! Thank you for sharing your knowledge. I'm going to go fix a couple TV's and some test gear this holiday weekend. Have an excellent holiday !
Hi! I just found you this morning and was a subscriber within the first five minutes :) I worked in a Mom & Pop Zenith shop from the early 80s to early 90s while this was going on and remember it well. We saw mainly loose, arcing horiz yoke connectors, with the same result. It would set that paper stuff on fire. Sometimes it would go out, sometimes not. If I recall correctly, it was a Zenith part# 9-186. I think they were first used in the 1984 System3 and Advanced System3 models with those pesky 9-181 and 9-214 chassis. Those were higher-end sets that usually came in a wood products cabinet.
UL had a test, starting in 1975, in which they'd pour alcohol into the set and light it; the set only passed if the fire burned out when the alcohol was consumed. I wonder if Zenith passed the test with pre-production parts, then switched suppliers. I've read that the EU relaxed the flammability standards on TVs in the 1990s when they banned a number of flame retardants; at one point, there were 100 times as many TV fires in EU countries as in the USA, including one famous fire in a UK "tower block" that killed 6 people.
I recall Zenith had some 4 leaded "safety capacitor" in the flyback circuit back in the 70's that also would fail and cause damage. I had an old 70's Zenith that had all the circuits on plug in modules. It was an erratic and annoying set, always failing. I got fed up and soldered all of the plug in modules making it no longer repairable by that means, yet it became very reliable after I did that. A friend's family had a small set that failed and I was asked to fix it. They had it upside down and were watching a sitcom. Apparently right side up it would fail. I took the back off and ran a small artists paint brush all over the PCB until I found the unsoldered part. They thought I was a genius.
Quasar "Works in a Drawer" set, with plug-in modules, were also known for bad connections. I believe one of the first thing Panasonic did when they bought out Quasar was to get rid of that system. I'll bet both Zenith and Quasar charged a mint for replacement modules.
40 + yrs at the TV bench at one of the biggest Zenith dealers in the Boston area. Love watching your vids, great memories. Now bench talk......... Maybe in Canada there was a fire recall but the only I recall we had on Zenith was the 4 lead caps. IIRC the law suits were over the damper tube sockets on 4 tube hybrids. So common I still remember the PN# 78-1888-01. No way they didnt have symptoms like SMOKE etc. Also paper in the HV area wasnt used till the Custom & Advanced System 3 @ 1983. A few H yoke plugs did toast up on them but again now way no symptoms. The only other thing was on some hybrids a huge disc cap would arc & burn a fiber board. The caps were called back & if you ordered one you would get a tripler kit to eliminate it. To sum it up our local distributors head tech told us " if any Zenith product goes into an open flame & does not stop when unpowered confiscate the set & call me immediately if not sooner. This was late 70's Best regards Tom LFOD !
Definitely in Canada. I probably still have the service bulletin for the system 3 deflection board that the linearity coil burnt up. I remember the 4 lead safety cap recall too, where they changed the white cylinder type for an orange dipped type, and the damper tube failure. There were several fires with these sets, most the board burnt up, and the set went dead, but there were a few where the set ignited, likely a console where the particle board cabinet caught. I do have a link to a news story below over one of the lawsuits. It was a Christmas day fire mid 80's. We got a bulletin from Zenith (as we were a warranty dealer at the time) that said that any set that came in within a specific serial number range that the deflection board needed to be inspected and if it didn't have a sticker on the shield that it needed to be replaced. The newer boards also had a white fiberglass shield as opposed to the gray one that looked like paper. Then another bulletin came out that said to resolder the horizontal linearity coil, flyback ect, and replace the old shield with the new one and affix a sticker to the back indicating it had been done. Now I don't know about in the USA, but here they had a few bulletins. They never issued a recall to the public telling them to not use the set as far as I know. It was just a bulletin for sets already in for service.
That paper is called Nomex. Nowadays though they use a Chinese equivalent. The cold solder joints are common to components with contacts with a large thermal mass. The wave soldering machine speed is too fast for the contact to heat up sufficiently for good adhesion. Surprisingly the joints look perfect to the eye despite them being poor. These slip through QA very often, even nowadays.
I know it's a bit off topic but here in the UK there are 5.3 MILLION tumble dryers that are being replaced by Hotpoint, Creda and Indesit - Whirlpool American owned. They too have caused many deaths all for the sake of a thermal cutout costing less than a cigarette. We went for the 'new option' that was less than half the price of a new one. If we had not it might have been several years before it was fixed. It now seems the so called fix isn't working and the repaired ones are still bursting into flames. I was hoping I could hang on to our old one (< 2 years old) and add a thermal cutout but they took it away. Our previous dryer had one - 10 for 99P off EBAY ? It seems that penny pinching has reached an all time high. Accountants, poor design and greed strike again.
It wasn't too badly charred so that's what flux is for, but I agree it would have made for a neater repair. When there's no severe charrin, I do use some wick and then the soldering iron as a scraping tool. When in doubt about the cap, I replace the cap. If needed, I use a small screwdriver for scraping. I don't like glassfiber pens, but if it is really bad, I use one.
Upon reviewing, the actual bad practice is tapping the capacitor and making it arc some more. Originally, there wouldn't have been much charring. Also, provoking arcing can blow up semiconductors.
It's such a shame that most tv's like that were made useless by crap lcd sets, the tube still looks good and the picture looks decent. I would often have to resolder the lopt, mounting heavy/hot parts with solder was always a recipe for failure, but we still liked the old sets, they lasted so dam long :-D. Hope you have a loverly xmas dave.
Not only was the old stuff reliable, but it is serviceable. The new stuff is not designed to be repaired. When it fails you toss it away and replace it.
I know and i feel quite sad about it, i know through hole components are not the best, but i hate smd because they are a shit to work on. And they fail because of pcb stress, capacitors just go short for no good reason ;-(. It's my excuse and i'm sticking to it ha ha :-D
Nope, not expensive sets, just change the faulty board, however its never happened to me anyway, been running daily for over 10 years with zero issues. you get what you pay for, there were bad vintage sets as well they are not immune.
Sure were. People have short memories. Some of the worst offenders were brands such as Motorola, Zenith, RCA, Curtus Mathis, Admiral. All american made. These were also some of the best ever made, and many of those old sets are still working today with few problems. When circuit boards were introduced in the tube era there were many troubles just due to the heat from the tubes. One of the nicest TVs I ever had, which was also a problematic set was the Philips K6 and Modular 4. The K6 was plauged with connection problems, and the modular 4 with bad plugs on the module connectors. Zenith also had huge problems with the module connections as did Motorola with the Quazar brand with the worksin a drawer. Remember them. All the boards were in a drawer that the service man could access from the front. Just remove a screw from the back, and press a latch, and the chassis slid out on a track for service. The problem was the interlock disconnected so the back had to be removed so a cheater cord could be plugged in for service. Defeated the purpose. Ah the fun of vintage electronics.
I think most valve tube stuff in the 60s was a fire hazard anyway with all the heat and high voltage present. i know shango has to put fans in his old tvs, especially around the arcing flybacks, its never a good idea to leave old tube tvs running unattended.
I have a 1989 Zenith 13" (SF1315W, 9-795 chassis, Mexican-built set) that has some sort of arcing noise inside it. Occasionally the vertical jitters. I think it's the chopper. Should I _not_ be using this TV? Been using it about 12 hours a day for 2-3 weeks now.
Now for LCD TV, the 2012 RCA RLDED3258A and Proscan PLDV321300, the winding coil is almost about ready to catch fire and cause to go up in flames two and it's so ashamed that the manufactures don't care about making products that is safe because, they want you to pay more for either repair or replacement while they ranking in. That both RCA & Proscan LCD TVs did something without warning.
Here in Finland Salora and Finlux CRT TVs had a very similar problem(in the mid to late '90s). Basically the exact same thing, but with the yoke plug(s). The solder joints would start to decay, and one day it'd cause a big spark and set the TV on fire.
I have components from a modular deluxe System 3. It was set out on the curb with a busted CRT by the Salvation Army. I snatched all the boards, control drawer, 8 inch woofers and the tweeters. I noticed the high voltage board had a connecter burned off. I'm sure that made quite a stink. I'd like to have a working System 3 console like that in my collection. Add a Zenith with space phone too.
Yes those HV boards were notorious for burning up. As a serviceman for years, you learn real quick which brands of TVs you didn't want to have in your house. Zenith syetem3 was one of those.
I have been enjoying your videos. Very helpful. I am new to tv repairs. I have an older Sony kv-10fmr20 TV, radio. Unfortunately it just crapped out on me. It has audio but not picture. Any ideas what the problem could be?
Around 1986 an elderly lady on our block died from a house fire after TV in her bedroom caught fire. She called her son to come look at it but he got there too late amd already caught fire after she apparently fell asleep. I wonder if same issue.
It arced on the underside of the PCB where the solder connection came loose and it left carbon deposits around that arcing location. If there is HV on one of the capacitor pins then it may find its way across those carbon deposits on the PCB to another pin where it does not belong. I don´t know if there is enough HV on that cap but I think it is generally a good idea to clean the PCB after such incidents.
I once repaired my Sony TV which had a bad flyback that arced. When I switched it on with the new flyback it arced between some pins around the flyback base and fried a diode. After I cleaned the board all was well...
I also agree, it's always good practice to clean the board where ever you do work before putting in the new parts. Impurities in welding steel is bad for the weld, and when it comes to electrical welding (aka. soldering) it's just good practice. But in reality, the repair may outlast the TV....
This reminds me of the recall Sony had to to do with underated on/off switches here in the UK. A lot of engineers worked overtime to fit uprated switches due to the number of sets going on fire, i have seen the plastic fronts deformed by the heat from the cheap switches. Then we say that they don't make them this good anymore!
There were many safety bulletins issues for many products that you never heard about. Switches, wiring harnesses, fuses, mov ect that we had to do every time when a specific modem came in. Remember the flyback trouble on a certain model that was replaced long past warranty and the an orange dot sticker was stuck to the label indicating that it was done. Then pabasonic with their under sized wiring harness on thousands of microwave ovens, many that could very well still be in use. That one was never a fire safety hazard because if the harness overheated and shorted the worst thing that happened was the fuse would blow and when the tech opened it up he found the wires were melted together between the fuse and the switches. But there was a mod kit that was out at the time that you could order and it came with the wires all bundled and you just unplugged everything and put new ones on and they were heavier gauge wires. Lots of fuck ups and manufacturing over the years that were corrected by service centers that people never knew about. What I work for Sony we did the big recall on the 5000 series betamax machines that required I think I was around 45 or so capacitors in the servo board they were solid aluminum type capacitors made by Samuel and they were all swapped out for a little tantalum caps because the failure rate was about 100%. They were covered under warranty long past the one year warranty because it was such a big problem same solution I think those ones got a red dot stuck on the back when they were done. but if you've got full TV or an old microwave or an old VCR if you look on the back and you see there's a colored sticker that generally means that there was a recall done a soft recall and the unit was repaired while it was being serviced for something else.
We had exactly the same problem with TV sets in the UK of the same vintage. The scan coil [yoke] connector would become dry jointed and burn together with line linearity coils and scan coupling capacitors. That is what happens when you dip solder the entire board when it contains components that require more heat for the solder to flow correctly. J.
And when I manually solder these big terminals I get the trolls that have an iq of 69 telling me how I don't know how to solder and i am putting too much heat on, and how they can't watch and are unsubscribing as I am an "amateur". Fucking idiots haven't a clue. 40 years in the service industry has taught me a thing or 2 about insufficient heat on a solder joint.
@@12voltvids We had a major problem with a UK chassis that was rented out to customers by a leading rental company. The rental company was actually owned by the set maker! The line linearity coil became dry jointed probably due to the 'sing' of line frequency. It caused some major house fires and all the models were recalled and scrapped for fear of insurance claims. Another chassis suffered a dry jointed frame output transformers mounted on the P/C board itself. It was not a heavy component being a later model and just needed a bit more solder applied with a hot iron to the connecting tags. Push button mains switches when mounted directly onto the PC board were another hazard. Models with Thyristor line output stages suffered badly with dangerous dry joints on wound components due to the high current high frequency involved. I owned my TV service center/sales shop from November 1966 to December 2002 so I know I'll back you up with this one. Guys working with clean P/C boards from low voltage electronics simply don't understand the dangers of high voltage/ pulse arrangements in television receivers. Regards, J.
I played Halo on a widescreen CRT because the color is so much better and the speed isn't noticeable like LCD. Graphics are much higher than the 1280 the monitor did now, so to LCD it was, but for retro games...hell yea, if you have the space for CRT at least!
You mentioned about having one hand your pocket in case you get zapped. I'm a little confused. Is that so the electricity doesn't go throughout your body?
It was the 1980s when I was a kid and I was watching TV one day and I smelled smoke, I told my mom about it and she said turn the TV off now and I did and she found out that a vacuum tube was burned up so when my dad came home he replaced it with a new one.
Hi, use a 100w incandescent light bulb to discharge the high voltage filter caps etc. also you can use a 1.8k or 2.8k ohm 10 watt or higher resister to discharge as well. thank you.
You mention being able to sell these TVs for old games, infact you could probably get a good bit if you RGB modded some of the old Trinitron sets. Basically adapting RGB SCART to an North American TV basically via the jungle IC
narunetto The problem is these sets are all hot chassis so you can't just add external inputs. Those sets that do have external inputs also require isolation. Also these classic games here all are ntsc composite video based.
Apparently the people on this thread at a forum (shmups.system11.org/viewtopic.php?f=6&t=56155c) seem to be able to do it on the 90's sets, not being hot throughout. Also, they were mostly composite from the get-go, but systems like the SNES and Genesis actually have the 15khz RGB on them.
I have a question about that solderpoint you re-soldered, it was burned and i didn't see you cleaning it and just solder over it, won't that be a weak point afterall?
....... I was thinking identically, I would have 'wire wrapped' an additional line between the resistor & inductor. Have to keep in mind the multitasking of video production, our gender is not known for its mastery in this field. If he was working alone it would likely be different. You just want to wrap another video I assume.
if you had a spare camera you could connect it to a set with the camera pointing towards the screen of the faulty set and could see what was on the screen of the faulty set i really enjoyed watching your repair videos merry christmas and all the best for 2018 to you and your family and the cats of course donald and daisy the border collie in scotland
Just wondering have you seen the mods to put scart on a US tv I kinda want one for my old games and dvd players and such also can you make a tv with rf only have composite by taking out the rf modulator and wiring up some sort of input?
A t h s t e t i c A n d r o i d/GamingGutter The problem is this is a hot chassis so you can't just add a video input. You would need isolation circuitry. Isolation is done between the tuner and rf input. The coax connector is electrically isolated from the chassis.
12voltvids I meant it in context to using it as a " follow me on" and" support me on type of deal, I guess I should have mentioned that in my original post.
I have a couple of messages on it. One says paypal support followed by the info, and then the patreon info. Ican put any message into it, cool little display I got to evaluate.
The brand says General Electric but from the smd components and trimmers i would say that is definitely saba nordmende or thomson made tv chassis board.
GE and RCA never made it big in the UK but Thomson did, they made the early Sky Digital boxes and later Sky + and Sky + HD boxes, but they were very unreliable and had to be replaced by Pace (now Arris) or Amstrad Units, A relative had a (UK) RCA DVD player but i never got to see it working
no av in you say? most of polish tvs made by unimor in the 70's and 80's wern't designed to nativly support av intmut either. that is why in later years most of those tvs were either factory or privatly hacked to support "automatic av inputs" in neptun D505 there was no av, but factory designed special av module umm2003 if i remember corectly which depending on the revision could output signal from tuner on output terminals, or take in av signals on input terminals and cut off tuner path by simple diode based polarised circuit (2 diodes,3 resistors and 2 capacitors) the module was detecting synchronisation pulses and based on this enabled or disabled tuner default path and av passtrough i made this module for my tv with an added bonus of rgb input. i belive it could also work with ntsc reciever , because it intercept signals before color decoder for av and after color decoder for rgb (or more precisely r-y b-y, y paths just before matric module)it might be more work for jungle ic tv though, my reciever is fairly modular.
There is a shard of a mirror somewhere, one I stole from the shop I worked at. It's actually in behind the big plasma to the right of my work bench. Just can't be bothered to use it.
Well electronics engineering isn't a bad one. Myself over the 20 years I was in the business I took probably 100 or more electronics courses, most put on by the manufactures. When I first learned, I was taught by a private instructor that saw potential and took me in as a student when I was about 15. He was a master certified RCAF Radar / Radio enginneer from the air force. Forked on building radar and radio installations during the WW2, then went on to work building broadcast transmitters, and in the early 60's opened his own shop with one of his military buddies that he worked on Radar installations with. I knew his son from school, so I started hanging around the shop and helping out. It wasn't long before the owner asked if I wanted to really learn about electronics, as his own son was getting into it. So I would hang around there after school, and be put to work, and get lots of hands on, and theory. The owner retired and his business partner took over, and offered me a job. Did that though high school, wrote the CEASA challenge exam, and got my certification in 82. Next year I went to work for Sony, where I learned betamax, and applied that knowledge to VHS. Left Sony in 84 (because they wanted to transfer me across the country and my GF didn't want to move across the country) Landed at a certified warranty depot, and spent the next 19+ years at that shop. Retired from the business in 2003 and changed careers promising myself that I was done fixing electronics. Stayed away for about 10 years and due to pressure from clients started working on some types of electronics again.
This would require isolation as this is a hot chassis. This can be done 2 ways. Isolate the TV with an isolation transformer or isolate the video input with optical isolation.
DriveInFreak Yes I am fully aware of the ground problem on the rca/ge tuners. It was worst on the ctc 176/177/178 uni board that had the tuner built into the main board. Grounds would fail and corrupt the eeprom resulting in a dead set. I used to use a program on my laptop, probably still have it and I Made a interface cable with a clip to clip it onto the eeprom to reload default settings to get the set running again. If I remember I used chip pic software to load it.
Nice. I had to go through all the settings myself. I cut my teeth on those things as so many came in when I was getting started. I can't remember the sequence of buttons to push to get the eprom settings on the screen anymore, though. It's been too long.
Menu vol down and power wasn't it? Been along time for me too. I "got out" in 2003 and swore I wouldn't work on electronics anymore. Then is 2012 I started working on stuff again from time to time. Now, if I wanted to I could do it full time as I have people that ask me daily to fix their stuff. Most I decline as the modern junk just isn't worth fixing. I find the old stuff much more interesting. We used to have an unauthorized slogan for those. GE Garbage Engineering. RCA Requires Constant Adjustments JVC Junk Very Cheap. Sony Soon Only Not Yet
12voltvids no wonder zenith was sued over it highly flammable stuff I have seen some other Television boards that have caught fire what a mess not safe at all my grandfather had to deal with the famous zenith safety cap failures and if I recall some of the crts in those sets imploded when the cap failed
You said in the beginning that you were working on an RCA. It's clearly labeled a GE. Yes I know GE bought RCA and later sold to Thompson. But it is clearly a GE not an RCA.
Being from Europe, I only know products from the mother company, and the chassis just screams Thomson at the top of its lungs so it really doesn't matter that much which label is on it. It was clearly designed by the same staff that designed the French and Singapore made sets. Those were also soldered pretty badly.
Why? The little bit of carbon on the board isn't going to do anything. For starters there are no other traces involved that it can conduct to and this tv isn't going back into service. I found this set at the side of the road. It will be used in future videos for fault simulations at some point but other than that it won't be going back in service. So there was no point. If the burnt area was encroaching on other traces where there would be a possibility of cross over then the carbon would be cut away and hv silicone would have been used to fill the void and allowed to fully cure before the set powered up but that was not the case here.
bzzzt bzzzt bzzzzzt bzzzzzt. my fix was, scrape some trace coating, bend the leads over tight to the board and solder. alternately, wrap buss wire on the legs, scrape trace coating, lay it on the trace and solder. neither way is good for majorly burnt board that's turned to carbon or carbon tracked..
I'd say a good deinterlacer is a better option for old games. Interlacing was invented by the Devil, and multi-format widescreen CRTs are about as hard to find as a living George Harrison.
you do know why everyone was forced to do away with vhf/uhf ? Im pretty sure it was interfering with the govs HAARP weather manipulation program. LOL Ive keep a few nice big tube tvs, the Sony vega and an RCA wide screen. they work with an HD tuner box , but could use a tune up. And they are great for the kids/grand-kids playing video games. And have a Merry Christmas and Happy New Year, Dave.
I thought the infamous Zenith fault was the "critical safety capacitor". It was a 4-legged snubber cap across the HOT, 2 legs on each side of the cap, with B+ run through it. The idea was if the cap opened, it would kill the flyback's B+ supply and shut down the set. Problem was, the caps didn't fail open, they simply changed in value and caused the EHT to go up to over 50kV, arcing the neck right off the CRT and starting a fire.
The amount of knowledge and skill you have is truly amazing. This does not exist in modern world, just chuck it out and buy a new one.
Gotta love the Fred Flintstone pounding method of electronic repair.
How would you identify a bad connection location?
Love watching your videos. Thanks for all the hard work and effort you put into this channel.
Excellent repair and great ideas discussed. That was a fun long ago to fix such televisions!
One of the most common problems with electronics, cold solder joints. I've repaired many things just by touching up cold solder joints. I fixed my Ghetto Blaster boombox from the 80s which had weak audio output, it was simply not getting enough power. I guess the heat from the soldering iron woke up the main power filter cap.
Philips (EU) tv's had a similar recall early nineties after several tv's had burst into flame, and those were otherwise overengineered top of the line models that were produced in local factories still with overall excellent build quality, similar to the heydays of zenith. They had several vertically mounted boards where heat cycling and gravity killed the solder joints. I remember calling in the tv shop as a nosy kid after discovering the recall from a newspaper. That tv ended up having many, many hours of service without any other service until the tube was so dead all the colors started bleeding. Ended up swapping out the tube and giving it to a local charity where it was used for who knows how many more years.
It also definitely was a thing in those days to whack your older television because of the bad solder joints.
And a bit earlier, GE had double sided board problems due to griplets having a bad solder connection due to differential expansion. We'd hard wire the circuits that had griplet connection failures to avoid recalls. I remember one that drove me around the bend figuring out a griplet related issue that was unusual. I fixed it after much effort and literally sleepwalking to the basement shop, to awaken that morning to find it repaired and some notes that made no sense at all.
Yeah, I fixed the damned thing in my sleep.
Then, there was the RCA with an MOV failure, it let go fully as I was looking directly at it. Thankfully, I yanked the cord before it could burn the customer's hardwood floor.
And a Philco TV with an SCR horizontal output that had a similar problem to this set, the arc leaving me with a tiny blind spot to this very day...
I eventually became the guy other shops called when they couldn't figure out what the problem was.
The infamous 1993 K40 safety recall
@@edwinvp That one indeed! I hope to one day find myself another K40 again.
Funny, that failure is pretty much the same that got me my first TV in the early 90s. The one I got had an electrolytic capacitor with some other stuff in parallel to that big film cap. The film cap wiggled loose but it was by all means not visible. It made the electrolytic go boom eventually and the technicians could not figure it out. So it went to the bin when I got it. I did the same, replaced the electrolytic cap, and after a day - it popped. Reverted to "bombarding" everything with solder and then discovered that the film cap was actually loose. After that fix I used that TV until 2006 before I got a flat screen.
I remember an old RCA with a color problem. Eventually, I didn't have the time to play with it, so I sent it to a local RETS electronics school for repair - which they never managed to fix.
So, one holiday weekend after getting it back, I found a fractured solder joint on the delay line.
Needless to say, that was back before my arms started getting shorter... ;)
Looking forward to more tube TV repairs, I keep my CRTs going for gaming.
I remember walking home from school in 3rd grade and seeing my neighbor's 1964 RCA (CTC-16, probably) roundie color set out in the driveway with holes burnt through the area around the tuners. Their daughter had been watching Romper Room when it burst into flames; I've since heard that it was the thermistors that RCA used, to delay the power-up while the tubes were warming up, that caused such fires. Some sets from that era (Admiral & some others) were also known for fires that spread when wax dribbled out of the flyback. I worked on Zenith monitors from Mexico in the '80s and never saw such junk; those plants were going through labor conflicts and it showed in the lack of workmanship. I still have a 1988 GE stereo set (CTC-136) that had a similar problem to this, but it was a special capacitor in that area that looked like a ceramic disc, but was made of plastic and cost a lot more. It filled the room with smoke, but that was just the fusible line-dropping resistor doing its job. I replaced the cap with a ceramic one and the set has been fine ever since.
The Mexican zenith sets were some of the worst sets i ever saw.
Loved the really obvious sound edit at 5:42 ;-)
12voltvids lol. You are so considerate for your viewers ;-)
system 3...lol
Über 30 Jahre Berufserfahrung, wau. Dein Wissen ist phenomenal! Ich liebe Deine Videos. Thx.
I love your repairs on TV's . You're literally one of my favorite TH-camrs.
Stay tuned. I have a vintage radio from the late 20's to go up, and another vintage technology digital clock build that uses 6 VFD tubes. Been waiting months for a package from Japan, and it finally arrived.
There are guys in the retrogaming scene that are trying to make an RGB input for these old tubes, so they can get the most out of the tube and the console. In this case, there is no sound input, but I'm guessing that if you can get an RGB input signal working, you can also get an audio signal in. That's a nice project (and tutorial), that will also give new value to these old TV's with no inputs other than RF.
The problem here is safety. These are AC line operated sets, and thus have a hot ground. That would be a major safety problem connecting anything to this or any other set like this. You would need to design an opto isolator. I should drag out my old Sony KV1965 and I can go though how sony put a video in on a hot chassis. They did it with optical isolation. Other companies did it with little transformers on the old sets. Then they went to switching power supplies to isolate the AV portion of the chassis from AC line. This one has neither so the only safe way to use this set as a monitor is to use an RF modulator, or plug the set into an isolation transformer.
I've found that if any of these sets were abused by poor handling as one might expect these connections would easily fail. A good number were all abused and dropped on the floor situations causing multiple damaged circuits that are really beyond any reliable repair.
Merry Christmas to you and your family! I wish you good health and may your videos next year be as interesting as they were up to now.
Your videos are inspirational and motivational ! Thank you for sharing your knowledge. I'm going to go fix a couple TV's and some test gear this holiday weekend. Have an excellent holiday !
R. Flynn
I'm building a 6 digit vacuum fluorescent display clock with separate tubes. Video to follow.
Hi! I just found you this morning and was a subscriber within the first five minutes :) I worked in a Mom & Pop Zenith shop from the early 80s to early 90s while this was going on and remember it well. We saw mainly loose, arcing horiz yoke connectors, with the same result. It would set that paper stuff on fire. Sometimes it would go out, sometimes not. If I recall correctly, it was a Zenith part# 9-186. I think they were first used in the 1984 System3 and Advanced System3 models with those pesky 9-181 and 9-214 chassis. Those were higher-end sets that usually came in a wood products cabinet.
UL had a test, starting in 1975, in which they'd pour alcohol into the set and light it; the set only passed if the fire burned out when the alcohol was consumed. I wonder if Zenith passed the test with pre-production parts, then switched suppliers. I've read that the EU relaxed the flammability standards on TVs in the 1990s when they banned a number of flame retardants; at one point, there were 100 times as many TV fires in EU countries as in the USA, including one famous fire in a UK "tower block" that killed 6 people.
I recall Zenith had some 4 leaded "safety capacitor" in the flyback circuit back in the 70's that also would fail and cause damage. I had an old 70's Zenith that had all the circuits on plug in modules. It was an erratic and annoying set, always failing. I got fed up and soldered all of the plug in modules making it no longer repairable by that means, yet it became very reliable after I did that. A friend's family had a small set that failed and I was asked to fix it. They had it upside down and were watching a sitcom. Apparently right side up it would fail. I took the back off and ran a small artists paint brush all over the PCB until I found the unsoldered part. They thought I was a genius.
Quasar "Works in a Drawer" set, with plug-in modules, were also known for bad connections. I believe one of the first thing Panasonic did when they bought out Quasar was to get rid of that system. I'll bet both Zenith and Quasar charged a mint for replacement modules.
"By George, I'm in the Area!"
Now that's a great t-shirt idea! 😆
40 + yrs at the TV bench at one of the biggest Zenith dealers in the Boston area. Love watching your vids, great memories. Now bench talk.........
Maybe in Canada there was a fire recall but the only I recall we had on Zenith was the 4 lead
caps. IIRC the law suits were over the damper tube sockets on 4 tube hybrids. So common
I still remember the PN# 78-1888-01. No way they didnt have symptoms like SMOKE etc.
Also paper in the HV area wasnt used till the Custom & Advanced System 3 @ 1983.
A few H yoke plugs did toast up on them but again now way no symptoms. The only other
thing was on some hybrids a huge disc cap would arc & burn a fiber board. The caps were
called back & if you ordered one you would get a tripler kit to eliminate it.
To sum it up our local distributors head tech told us " if any Zenith product goes into an
open flame & does not stop when unpowered confiscate the set & call me immediately
if not sooner. This was late 70's
Best regards
Tom
LFOD !
Definitely in Canada. I probably still have the service bulletin for the system 3 deflection board that the linearity coil burnt up.
I remember the 4 lead safety cap recall too, where they changed the white cylinder type for an orange dipped type, and the damper tube failure.
There were several fires with these sets, most the board burnt up, and the set went dead, but there were a few where the set ignited, likely a console where the particle board cabinet caught. I do have a link to a news story below over one of the lawsuits. It was a Christmas day fire mid 80's. We got a bulletin from Zenith (as we were a warranty dealer at the time) that said that any set that came in within a specific serial number range that the deflection board needed to be inspected and if it didn't have a sticker on the shield that it needed to be replaced. The newer boards also had a white fiberglass shield as opposed to the gray one that looked like paper. Then another bulletin came out that said to resolder the horizontal linearity coil, flyback ect, and replace the old shield with the new one and affix a sticker to the back indicating it had been done. Now I don't know about in the USA, but here they had a few bulletins. They never issued a recall to the public telling them to not use the set as far as I know. It was just a bulletin for sets already in for service.
That paper is called Nomex. Nowadays though they use a Chinese equivalent.
The cold solder joints are common to components with contacts with a large thermal mass. The wave soldering machine speed is too fast for the contact to heat up sufficiently for good adhesion. Surprisingly the joints look perfect to the eye despite them being poor. These slip through QA very often, even nowadays.
I know it's a bit off topic but here in the UK there are 5.3 MILLION tumble dryers that are being replaced by Hotpoint, Creda and Indesit - Whirlpool American owned. They too have caused many deaths all for the sake of a thermal cutout costing less than a cigarette. We went for the 'new option' that was less than half the price of a new one. If we had not it might have been several years before it was fixed. It now seems the so called fix isn't working and the repaired ones are still bursting into flames. I was hoping I could hang on to our old one (< 2 years old) and add a thermal cutout but they took it away. Our previous dryer had one - 10 for 99P off EBAY ? It seems that penny pinching has reached an all time high. Accountants, poor design and greed strike again.
A trip down memory lane, remember Zenith modular TV's with wire wrap connections is the chassis?
Yes unfortunately.
Damn, that set has a hell of a loud high pitched whine.
All CRT TVs do that
Some are more noticeable than others
Wow, you don't even prep the bad joint and clean the carbon off the cap lead and PCB land. That's what I'd call a bad soldering practice.
It wasn't too badly charred so that's what flux is for, but I agree it would have made for a neater repair. When there's no severe charrin, I do use some wick and then the soldering iron as a scraping tool. When in doubt about the cap, I replace the cap. If needed, I use a small screwdriver for scraping. I don't like glassfiber pens, but if it is really bad, I use one.
Upon reviewing, the actual bad practice is tapping the capacitor and making it arc some more. Originally, there wouldn't have been much charring. Also, provoking arcing can blow up semiconductors.
It's such a shame that most tv's like that were made useless by crap lcd sets, the tube still looks good and the picture looks decent.
I would often have to resolder the lopt, mounting heavy/hot parts with solder was always a recipe for failure, but we still liked the old sets, they lasted so dam long :-D.
Hope you have a loverly xmas dave.
Not only was the old stuff reliable, but it is serviceable. The new stuff is not designed to be repaired. When it fails you toss it away and replace it.
I know and i feel quite sad about it, i know through hole components are not the best, but i hate smd because they are a shit to work on.
And they fail because of pcb stress, capacitors just go short for no good reason ;-(.
It's my excuse and i'm sticking to it ha ha :-D
Nope, not expensive sets, just change the faulty board, however its never happened to me anyway, been running daily for over 10 years with zero issues. you get what you pay for, there were bad vintage sets as well they are not immune.
Sure were. People have short memories. Some of the worst offenders were brands such as Motorola, Zenith, RCA, Curtus Mathis, Admiral. All american made. These were also some of the best ever made, and many of those old sets are still working today with few problems.
When circuit boards were introduced in the tube era there were many troubles just due to the heat from the tubes.
One of the nicest TVs I ever had, which was also a problematic set was the Philips K6 and Modular 4. The K6 was plauged with connection problems, and the modular 4 with bad plugs on the module connectors. Zenith also had huge problems with the module connections as did Motorola with the Quazar brand with the worksin a drawer. Remember them. All the boards were in a drawer that the service man could access from the front. Just remove a screw from the back, and press a latch, and the chassis slid out on a track for service. The problem was the interlock disconnected so the back had to be removed so a cheater cord could be plugged in for service.
Defeated the purpose. Ah the fun of vintage electronics.
I think most valve tube stuff in the 60s was a fire hazard anyway with all the heat and high voltage present. i know shango has to put fans in his old tvs, especially around the arcing flybacks, its never a good idea to leave old tube tvs running unattended.
That's a nasty one for sure! Good old NAFTA hard at work.
I have a 1989 Zenith 13" (SF1315W, 9-795 chassis, Mexican-built set) that has some sort of arcing noise inside it. Occasionally the vertical jitters. I think it's the chopper. Should I _not_ be using this TV? Been using it about 12 hours a day for 2-3 weeks now.
Frohe Weihnachten für Dich und deine Familie.
Now for LCD TV, the 2012 RCA RLDED3258A and Proscan PLDV321300, the winding coil is almost about ready to catch fire and cause to go up in flames two and it's so ashamed that the manufactures don't care about making products that is safe because, they want you to pay more for either repair or replacement while they ranking in. That both RCA & Proscan LCD TVs did something without warning.
Here in Finland Salora and Finlux CRT TVs had a very similar problem(in the mid to late '90s). Basically the exact same thing, but with the yoke plug(s). The solder joints would start to decay, and one day it'd cause a big spark and set the TV on fire.
Still have my Salora 28" 'Täyskuva-TV' from 1986, working great! :'D
I have components from a modular deluxe System 3. It was set out on the curb with a busted CRT by the Salvation Army. I snatched all the boards, control drawer, 8 inch woofers and the tweeters. I noticed the high voltage board had a connecter burned off. I'm sure that made quite a stink. I'd like to have a working System 3 console like that in my collection. Add a Zenith with space phone too.
Yes those HV boards were notorious for burning up. As a serviceman for years, you learn real quick which brands of TVs you didn't want to have in your house. Zenith syetem3 was one of those.
I have been enjoying your videos. Very helpful. I am new to tv repairs. I have an older Sony kv-10fmr20 TV, radio. Unfortunately it just crapped out on me. It has audio but not picture. Any ideas what the problem could be?
Around 1986 an elderly lady on our block died from a house fire after TV in her bedroom caught fire. She called her son to come look at it but he got there too late amd already caught fire after she apparently fell asleep. I wonder if same issue.
Perfect for use with vintage game systems!
It doesn't matter how small the screen is , you soon forget the size when you sink in to it . 👍
Better clean that carbon deposits off of the board around the arcing point or it may arc again.
Arc to where? Nothing around it to arc to.
It arced on the underside of the PCB where the solder connection came loose and it left carbon deposits around that arcing location. If there is HV on one of the capacitor pins then it may find its way across those carbon deposits on the PCB to another pin where it does not belong. I don´t know if there is enough HV on that cap but I think it is generally a good idea to clean the PCB after such incidents.
I once repaired my Sony TV which had a bad flyback that arced. When I switched it on with the new flyback it arced between some pins around the flyback base and fried a diode. After I cleaned the board all was well...
RE: "Better clean that carbon deposits". You couldn't be more righter :) At the very least it's good practice. Period. Cheers!
I also agree, it's always good practice to clean the board where ever you do work before putting in the new parts. Impurities in welding steel is bad for the weld, and when it comes to electrical welding (aka. soldering) it's just good practice. But in reality, the repair may outlast the TV....
Nice plastic/wood cabinet 😀
This reminds me of the recall Sony had to to do with underated on/off switches
here in the UK.
A lot of engineers worked overtime to fit uprated switches due to the number of sets
going on fire, i have seen the plastic fronts deformed by the heat from the cheap switches.
Then we say that they don't make them this good anymore!
There were many safety bulletins issues for many products that you never heard about. Switches, wiring harnesses, fuses, mov ect that we had to do every time when a specific modem came in. Remember the flyback trouble on a certain model that was replaced long past warranty and the an orange dot sticker was stuck to the label indicating that it was done. Then pabasonic with their under sized wiring harness on thousands of microwave ovens, many that could very well still be in use. That one was never a fire safety hazard because if the harness overheated and shorted the worst thing that happened was the fuse would blow and when the tech opened it up he found the wires were melted together between the fuse and the switches. But there was a mod kit that was out at the time that you could order and it came with the wires all bundled and you just unplugged everything and put new ones on and they were heavier gauge wires. Lots of fuck ups and manufacturing over the years that were corrected by service centers that people never knew about. What I work for Sony we did the big recall on the 5000 series betamax machines that required I think I was around 45 or so capacitors in the servo board they were solid aluminum type capacitors made by Samuel and they were all swapped out for a little tantalum caps because the failure rate was about 100%. They were covered under warranty long past the one year warranty because it was such a big problem same solution I think those ones got a red dot stuck on the back when they were done. but if you've got full TV or an old microwave or an old VCR if you look on the back and you see there's a colored sticker that generally means that there was a recall done a soft recall and the unit was repaired while it was being serviced for something else.
We had exactly the same problem with TV sets in the UK of the same vintage. The scan coil [yoke] connector would become dry jointed and burn together with line linearity coils and scan coupling capacitors. That is what happens when you dip solder the entire board when it contains components that require more heat for the solder to flow correctly. J.
And when I manually solder these big terminals I get the trolls that have an iq of 69 telling me how I don't know how to solder and i am putting too much heat on, and how they can't watch and are unsubscribing as I am an "amateur". Fucking idiots haven't a clue. 40 years in the service industry has taught me a thing or 2 about insufficient heat on a solder joint.
@@12voltvids We had a major problem with a UK chassis that was rented out to customers by a leading rental company. The rental company was actually owned by the set maker! The line linearity coil became dry jointed probably due to the 'sing' of line frequency. It caused some major house fires and all the models were recalled and scrapped for fear of insurance claims. Another chassis suffered a dry jointed frame output transformers mounted on the P/C board itself. It was not a heavy component being a later model and just needed a bit more solder applied with a hot iron to the connecting tags. Push button mains switches when mounted directly onto the PC board were another hazard. Models with Thyristor line output stages suffered badly with dangerous dry joints on wound components due to the high current high frequency involved. I owned my TV service center/sales shop from November 1966 to December 2002 so I know I'll back you up with this one. Guys working with clean P/C boards from low voltage electronics simply don't understand the dangers of high voltage/ pulse arrangements in television receivers. Regards, J.
@@vinylseat they don't know anything about high power connections but you can't fix stupid.
Nice we had the same issue at school on a crt computer screen back in 2007 keep it up...
CRT and retro Gaming is a must!!! Nice video
Joshi Oyabun
Yes I know. I have no problem selling crt sets I fix just for retro gaming.
I played Halo on a widescreen CRT because the color is so much better and the speed isn't noticeable like LCD. Graphics are much higher than the 1280 the monitor did now, so to LCD it was, but for retro games...hell yea, if you have the space for CRT at least!
You mentioned about having one hand your pocket in case you get zapped. I'm a little confused. Is that so the electricity doesn't go throughout your body?
more so it doesnt go across your chest, possibly stopping your heart!
That's interesting that it was the capacitor at fault. And that the connection was burned.
It was the 1980s when I was a kid and I was watching TV one day and I smelled smoke, I told my mom about it and she said turn the TV off now and I did and she found out that a vacuum tube was burned up so when my dad came home he replaced it with a new one.
Do you have videos on discharging? That's my biggest fear once opening stuff. I tinker with VCRs
Hi, use a 100w incandescent light bulb to discharge the high voltage filter caps etc. also you can use a 1.8k or 2.8k ohm 10 watt or higher resister to discharge as well. thank you.
Looks like one of those that were made when GE and RCA were Thomson Consumer Electronics. Board looks like Toshiba.
Nice to watch before I get a CRT in the mail!
WoW, a second anode lead wire...whooo, been a while, got bit by one 20 years ago while on bench, right in da groin area
You mention being able to sell these TVs for old games, infact you could probably get a good bit if you RGB modded some of the old Trinitron sets. Basically adapting RGB SCART to an North American TV basically via the jungle IC
narunetto
The problem is these sets are all hot chassis so you can't just add external inputs. Those sets that do have external inputs also require isolation. Also these classic games here all are ntsc composite video based.
Apparently the people on this thread at a forum (shmups.system11.org/viewtopic.php?f=6&t=56155c) seem to be able to do it on the 90's sets, not being hot throughout. Also, they were mostly composite from the get-go, but systems like the SNES and Genesis actually have the 15khz RGB on them.
Wow, this little capacitor has 160v near to that one that you fixed.
Stupid Sony did the same with the TV Power Switch saga.
Someone’s house also burnt, and all Power switches were repaired under warranty
I want your skills. I still don't know which parts to avoid touching.
You learn quick if you touch the wrong one when energized. Lol 😁
No flyback adjustment for focus and brightness?
I have a question about that solderpoint you re-soldered, it was burned and i didn't see you cleaning it and just solder over it, won't that be a weak point afterall?
....... I was thinking identically, I would have 'wire wrapped' an additional line between the resistor & inductor.
Have to keep in mind the multitasking of video production, our gender is not known for its mastery in this field. If he was working alone it would likely be different. You just want to wrap another video I assume.
if you had a spare camera you could connect it to a set with the camera pointing towards the screen of the faulty set and could see what was on the screen of the faulty set
i really enjoyed watching your repair videos merry christmas and all the best for 2018 to you and your family and the cats of course
donald and daisy the border collie in scotland
Mirrors work really good for that.
The logo on this tv looked like it was a General Electric one
Just wondering have you seen the mods to put scart on a US tv I kinda want one for my old games and dvd players and such also can you make a tv with rf only have composite by taking out the rf modulator and wiring up some sort of input?
A t h s t e t i c A n d r o i d/GamingGutter
The problem is this is a hot chassis so you can't just add a video input. You would need isolation circuitry. Isolation is done between the tuner and rf input. The coax connector is electrically isolated from the chassis.
What do you use to transmit analog signal I would like to know so I can do it
]Hey look. It’s a ‘flat screen tv’. *badum ‘tis
13:05 ah, I see what you did in the background there behind the tv with the text scroller there. :D ;)
morgan russman
That's how people can support my channel as an alternative to patreon.
12voltvids I meant it in context to using it as a " follow me on" and" support me on type of deal, I guess I should have mentioned that in my original post.
I have a couple of messages on it. One says paypal support followed by the info, and then the patreon info.
Ican put any message into it, cool little display I got to evaluate.
Was this television set actually made in Indiana or the land of the tacos?
Please keep teaching us
Well that's the idea.
RCA? Are you sure its not GE?
Here is a link to the Zenith fires I was referring to.
th-cam.com/video/czwlnzEvwUg/w-d-xo.html
hmm, dry joint...hate to think how many dry joints i've redone in the late 80s to late 90s, mostly ITT or Philips !
there was an ITT chassis that always developed a bad dry joint on one particular scan coil plug pin, caused bad burn ups
Ah, the Thomson crap wave solder phenomenon.
The brand says General Electric but from the smd components and trimmers i would say that is definitely saba nordmende or thomson made tv chassis board.
This was a Thomson set. They owned RCA and GE at this time.
GE and RCA never made it big in the UK but Thomson did, they made the early Sky Digital boxes and later Sky + and Sky + HD boxes, but they were very unreliable and had to be replaced by Pace (now Arris) or Amstrad Units, A relative had a (UK) RCA DVD player but i never got to see it working
Hi, good video well explained quick fix. Thank you.
no av in you say?
most of polish tvs made by unimor in the 70's and 80's wern't designed to nativly support av intmut either. that is why in later years most of those tvs were either factory or privatly hacked to support "automatic av inputs"
in neptun D505 there was no av, but factory designed special av module umm2003 if i remember corectly which depending on the revision could output signal from tuner on output terminals, or take in av signals on input terminals and cut off tuner path by simple diode based polarised circuit (2 diodes,3 resistors and 2 capacitors)
the module was detecting synchronisation pulses and based on this enabled or disabled tuner default path and av passtrough
i made this module for my tv with an added bonus of rgb input. i belive it could also work with ntsc reciever , because it intercept signals before color decoder for av and after color decoder for rgb (or more precisely r-y b-y, y paths just before matric module)it might be more work for jungle ic tv though, my reciever is fairly modular.
No mirror? With the amount of stuff you have around your work space I am sure there is a mirror there somewhere.
There is a shard of a mirror somewhere, one I stole from the shop I worked at.
It's actually in behind the big plasma to the right of my work bench. Just can't be bothered to use it.
What courses do you need to do these type of repairs ?
Well electronics engineering isn't a bad one. Myself over the 20 years I was in the business I took probably 100 or more electronics courses, most put on by the manufactures. When I first learned, I was taught by a private instructor that saw potential and took me in as a student when I was about 15. He was a master certified RCAF Radar / Radio enginneer from the air force. Forked on building radar and radio installations during the WW2, then went on to work building broadcast transmitters, and in the early 60's opened his own shop with one of his military buddies that he worked on Radar installations with.
I knew his son from school, so I started hanging around the shop and helping out. It wasn't long before the owner asked if I wanted to really learn about electronics, as his own son was getting into it. So I would hang around there after school, and be put to work, and get lots of hands on, and theory.
The owner retired and his business partner took over, and offered me a job. Did that though high school, wrote the CEASA challenge exam, and got my certification in 82. Next year I went to work for Sony, where I learned betamax, and applied that knowledge to VHS. Left Sony in 84 (because they wanted to transfer me across the country and my GF didn't want to move across the country) Landed at a certified warranty depot, and spent the next 19+ years at that shop. Retired from the business in 2003 and changed careers promising myself that I was done fixing electronics. Stayed away for about 10 years and due to pressure from clients started working on some types of electronics again.
Did "banging the TV" really help to find fault?
Percussive maintenance is very useful for fixing/finding problems
Yes.
I fixed monitors too, yes they burned but all metal no paper. That's commercial vs cheap consumer crap
You cracked the top of the tv.
I did?
Perry Robert, no child. That’s called wood grain. It was a common sight on TVs up to the 1980s.
Could you ether use mono for your voice or just mono the whole video.?
Intro song?
While you have it apart why dont you add RGB input to it for old video games?
This would require isolation as this is a hot chassis. This can be done 2 ways. Isolate the TV with an isolation transformer or isolate the video input with optical isolation.
Would it be fair to say that this was a quality control issue, if this set has not been touch since date of MFG?
Probably more of a design issue that the capacitor terminal gets warm enough that the solder fails after time.
Oh how I hated the 9-160 boards....
Cold solder, so many times it's the problem on older units
Not just older units. Newer units also suffer from this problem
Every one of those GE/RCAs had bad ground joints on the tuner...and I mean ALL of them.
DriveInFreak
Yes I am fully aware of the ground problem on the rca/ge tuners. It was worst on the ctc 176/177/178 uni board that had the tuner built into the main board. Grounds would fail and corrupt the eeprom resulting in a dead set. I used to use a program on my laptop, probably still have it and I Made a interface cable with a clip to clip it onto the eeprom to reload default settings to get the set running again. If I remember I used chip pic software to load it.
Nice. I had to go through all the settings myself. I cut my teeth on those things as so many came in when I was getting started.
I can't remember the sequence of buttons to push to get the eprom settings on the screen anymore, though. It's been too long.
Menu vol down and power wasn't it?
Been along time for me too. I "got out" in 2003 and swore I wouldn't work on electronics anymore. Then is 2012 I started working on stuff again from time to time. Now, if I wanted to I could do it full time as I have people that ask me daily to fix their stuff. Most I decline as the modern junk just isn't worth fixing. I find the old stuff much more interesting.
We used to have an unauthorized slogan for those.
GE Garbage Engineering.
RCA Requires Constant Adjustments
JVC Junk Very Cheap.
Sony Soon Only Not Yet
How hard is it to add a composite video input to a TV like this?
Cliff Miller it's not feasible the framerate is wrong, etc, is off
Just a composite to RF modulator will do the job.
Bad quality parts but at least these TV's are easy fix
Looked to me as if they completely failed to solder that properly
That was the problem with wave soldering that they used to do.
i think its called fish paper, i have seen quite a bit of it in electronics
Wendell Porter
Lot was brown stiff with fiberglass woven in like those old fiberglass pc boards. It would burn
12voltvids no wonder zenith was sued over it highly flammable stuff I have seen some other Television boards that have caught fire what a mess not safe at all my grandfather had to deal with the famous zenith safety cap failures and if I recall some of the crts in those sets imploded when the cap failed
Perhaps SRBP was specified, but non fire retardant (i.e. cheaper) phenolic paper was substituted.
It was usually the actual PCB that burned. A big hole around the linearity coil.
I never was a big RCA fan. They always had solder issues as did the GE's under the Thompson brand
If in doubt, give it a clout 😀
enjoyed the video....
You said in the beginning that you were working on an RCA. It's clearly labeled a GE. Yes I know GE bought RCA and later sold to Thompson. But it is clearly a GE not an RCA.
Being from Europe, I only know products from the mother company, and the chassis just screams Thomson at the top of its lungs so it really doesn't matter that much which label is on it. It was clearly designed by the same staff that designed the French and Singapore made sets. Those were also soldered pretty badly.
This is weird, why not cleaning that issue first and solder afterwards, all that carbon is still out there.
Why? The little bit of carbon on the board isn't going to do anything. For starters there are no other traces involved that it can conduct to and this tv isn't going back into service. I found this set at the side of the road. It will be used in future videos for fault simulations at some point but other than that it won't be going back in service. So there was no point. If the burnt area was encroaching on other traces where there would be a possibility of cross over then the carbon would be cut away and hv silicone would have been used to fill the void and allowed to fully cure before the set powered up but that was not the case here.
@@12voltvids Ok thnx man, i was just wondering, you're the expert and i'm always interested in your video's.
Wow...Just Wack it...wow people died that's insane...
bzzzt bzzzt bzzzzzt bzzzzzt. my fix was, scrape some trace coating, bend the leads over tight to the board and solder. alternately, wrap buss wire on the legs, scrape trace coating, lay it on the trace and solder. neither way is good for majorly burnt board that's turned to carbon or carbon tracked..
A bad yoke is because there are no good komedians in da house
Da yoke's on vu
Nice
That's a boat anchor, not a TV!
I'd say a good deinterlacer is a better option for old games. Interlacing was invented by the Devil, and multi-format widescreen CRTs are about as hard to find as a living George Harrison.
You have a dry joint 😊
Ya think!?
Buzzt!
you do know why everyone was forced to do away with vhf/uhf ?
Im pretty sure it was interfering with the govs HAARP weather manipulation program. LOL Ive keep a few nice big tube tvs, the Sony vega and an RCA wide screen. they work with an HD tuner box , but could use a tune up. And they are great for the kids/grand-kids playing video games.
And have a Merry Christmas and Happy New Year, Dave.
Looks like a G.E.