Yea once you get rid of these tin whiskers, spray the board with silicone lubricant, also tinning the leads of the transistors cures the problem permanently
Nice find/ fix Dave. The tin whiskers was something I heard about the electronics from NASA which developed from solder particles thus TIN which seemed to ionize with voltage and reattach themselves on a nearby metallic conductor or solder joint. I think changing the cause - tin / lead solder, was why solder content was changed. Do you think a clean nylon paint brush and compressor would help eliminate them ?
Tin whiskers are an allotrope of tin that has a very loose structure, they are not caused by oxidisation; search for Cody's video about tin pest to see what it looks like on a larger scale. I'm aware it's an issue on lead free circuits because the lead helped prevent the whiskers from forming, so I'm surprised to see it on such an old piece of equipment.
Annoying neighbours, yap yap yap ... sometimes you may wonder if they ever shut up. Tin whiskers - a big problem with some vintage tube equipment. But you sorted the fault out quickly by de-whiskering the transistors and got that receiver working fully once again - winner.
I had several Loudmouth neighbors move in accross the street. always know when they are up and about! she bellows like a bull buffalo when she calls her dog, laughs like a hiyena when she hears a joke, waddles like a penguin when she walks to the car. and I always know when their brats and them exit the car by the resounding slamming of the doors. I call them the "Slam-Bangers"
Hello Again I Have to reiterate I love watching you repair electronic devices but I also like watching you repair electrical stuff as well Your videos are always interesting and very informative Also I have to say it again I love your MGM CAT
This vdo helped me immensely.thankyou very much. I replaced my output caps on my sansui 777D . And a few transistors . But my speakers started a slow rhythmic in and out move. Im gonna follow the checkups like you have done in this vdo. Hopefully i wont need a tech..thanks alot .
Amps with high negative feedback are quicker to trace with a scope as the stage not working will have a serious voltage shift that is not being conducted to the next stage.
Nice looking receiver. Those always looked better in my opinion. Would putting plastic tubing on the transistor leads prevent tin whiskers? Just an idea. Or maybe Gillette has an idea.
When I was working we had some very clever people trying to figure out how to stop tin whiskers with not much success. I guess they will remain one of those things on the check list.
Hi,Joe from Nairobi Kenya.big fan of your channel.so last week got myself a technics SU-X302 amp. Worked well at first , but when i got home n hooked it up to my speakers, played for about 2 minutes then went mute.Took it apart, tried fixing any possible cold joints,put it back together , worked for another minute or so then cut out....i then got into the input board and recapped it all,still no sound. could it be a burnt IC?It uses SVI 3102C chip.I dont suspect the chip since from time to time it does give sound.I have tried checking all voltages around most of the transistors and chips ,everything checks out as per the service manual.I am really puzzled.please help
Crazy shit. How the voltage can jump the legs of the transistors through those fuzzies is fascinating. If it was an amp I was restoring, I'd probably replace those transistors (and caps) altogether, but to just get it back up and running, that's a great fix.
Electone_Guy Why change perfectly good transistors and caps just for the sake of changing them? Most caps will never fail nor will transistors unless they are either defective in manufacturing and if that was the case they would have failed years ago. Or they are overloaded. Solid state devices that have been properly manufactures rarely fail. The changes of getting a cheap knock off and having that part fail are greater then the original. Some of the early transistors were noisy, but if they are functional just leave em alone. Same for caps. With electrolytic only the ones with the big ripple are the ones getting a workout. The small coupling caps are not under stress and unless they were damaged during assembly they will likely be ok. These were from before they went to water based electrolytic. Dont believe me? Pull some and measure them. You will be surprised. Caps are the most likely component to fail this is true but it is certain caps. Ones involved in high current and high frequency. Switch mode power supplies, vertical ramp circuit in sweep circuits. I've been doing this for 35 years and I have never shotgunned a piece of equipment just because i could. Besides costing the client much more, which likely will tip the scale between repair or replace, you also run the risk that the new caps will be of inferior quality to the originals and in audio equipment this can completely change the sound.
Oh, I agree with you. Some people I do work for just want everything changed. Personally, when I do a restoration, I usually change out all the power supply caps whether they need it or not and I will replace caps in the audio path with "audio grade caps". Yeah, it's probably a load of bull, but it just a hobby. I really like the Nichicon UPW caps for power supply work and Nichicon UKL low-leakage for those old orange coloured caps. And if you get a piece of equipment from NAD, they are usually loaded with horrible Chinese/Taiwanese caps that do fail.
Preventative maintenance, capacitors are shit, always have been, number one failure part in all old electronics. also capacitor technology has come a long long way since the 70s, when they fail they can do more damage, its easier to just change them and not fuck about even testing them.
Right, and if you have someone that says knock yourself out change all the caps here is 500.00. But they don't. They say can you fix my stereo for 50 bucks. And for that they get the problem fixed and nothing more. I'll chance them all out on tube radios, because those ones do fail, but the ones made in the 70's and 80's were pretty good. They don't fail as often as you think. The biggest problem was and still is bad solder connections.
@@12voltvids yes, I come across plenty dry joints, some amps Ive done were full of them! I bought a technics M10 cassette deck nice and cheap, and the thing sounded odd - like a fuzzy distortion in the audio. For some reason most of its caps were leaking from thier pins, so I had to do a full recap which was tedious work. Only did it as I love the old hifi gear, anyway did that, cleaned all switches, new belts ect and now it's a lovely working deck. I got another M10 but a black one, I replaced the power caps only in that one as the other caps seemed ok. Here's a question: the black one is from Germany with '220v' input, the other one is 240v. So, why would one deck need full recap and not the other? Maybe stored in different temperatures?
Its the simple minds, those with the lower IQs that need everything put in it's place. Geniuses don't require this, as they can remember exactly where they left something. Ever see Albert Einsteins desk? "Does keeping a messy desk make you more creative? Working at a messy desk may actually help you think more creatively, according to a new scientific study. Scientists found that being surrounded by clutter can promote creative thinking and stimulate new ideas.Aug 6, 2013"
Bit OT, but I'd like some advice: have a Sony STR-GX47ES receiver, bought cheap, but it has a problem w/ the left channel. Upon, a cold power-up, if the volume isn't set to about the 10 o'clock position (roughly one-third up), there's no left channel. If I power-up w/ it set to that "sweet-spot", the left kicks in, right after the relay click. From then on both channels will work fine. As for troubleshooting, I've tried cleaning the volume pot & reseating the ribbon cables that connect the volume board to the main board, but no dice. Any ideas?
I had since solved this problem -- a dirty speaker selection switch. But now I've recently acquired a STR-GX49ES, identical to the 47 (adds a bit more RMS power). It's had the same problem, except it was the right channel not working.
Its the type of metals they used in the old days, especially mild steels that degrade with age, that along with atmospheric conditions contributes towards it. There are also a lot of alloys that are really good at turning into a sandpaper texture. Only high quality metals can be connected this close electrically without problems, which is why circuit boards are copper not steel (nothing to do with conductivity as silver would be the best anyway) and why new modern electronics parts are superior both with tolerances and specs/materials. remember in the 60s/70s all electronics mags touted their capacitors as being the best, but then there was no way of knowing this until modern technology arrived.
13:03 is that a Tantalum cap behind the transistor (it touched it when you bent the transistor over)? If so, I have seen from some of my other subscriptions that the green Tantalum caps are starting to fail short in older PC computer equipment. Might be worth keeping an eye on any tantalums in stuff you get in?
Very good video, as always. Could you give me some advice to open my own repair shop at home? I do not always have equipment to repair and I would like to know if you buy some equipment online that does not work to repair and sell. Thank you very much and greetings!
I don't buy equipment. I take donations of old equipment which I fix and sell, but more o it is stuff that is brought to me or repair. I ran a repair shop locally for 20 years, and have been doing repairs out o my house in the 15 since I let the business. 35 years in the electronics repair business.
Just a question when you find the whiskers and scrape them off shouldnt follow up with a good contact cleaner and flush the transistors and control boards? I would of flushed the boards before reinstalling them. I am no expert just a observation
Not necessary. They will grow back regardless. Flushing with cleaner can introduce more issues. We can't get the good cleaner that evaporates with zero residue anymore. Even 99% ipa has 1% water and that will leave minute residue if any minerals in it. Besides unless it is in a vacuum contaminants from the air will get to it. Better to leave the components alone. This stuff is so old it really shouldn't be working.
Ooow i didn't get a notification for this one :-(. And i only thought the Af117's got tin whiskers, but on the inside. Nice old transistor P.A, i thought the outputs were germanium untill you tested them. One happy owner :-D
That's something else, never would have thought of. I Never heard about that one either. For some reason I didn't get the link in my e-mail on this Vid?? I seen that someone else had the same problem, wonder why. Oh yeah forgot to ask, how pleased are you with your cordless screwdriver now that you have used it for a while?
I don't know what is up with youtube these days. I don't get half my notifications either. I am supposed to get an email of all comments and I get about 1 out of every 10 if I am lucky.
Pretty cool sleuthing skills there. Never would have thought of that. But, I just always cringe when I see someone using a power screwdriver around fragile components. Even in the hands of a pro it is just too easy to have it slip and run across a ceramic cap, zener diode or a transistor. Plus, they strip small phillips screws. I mean if its my own gear and I don't really care I guess that's one thing but someone else's receiver? Nope. Problem is that a lot of rookies watch these vids and think that's the way to go. Just use a normal screwdriver, take your time and be careful. They don't make this stuff anymore. Thanks for the video. Good one!
Well this was mine and this will make you cry. I recycled it after i was done with it. Had it up for sale for months. Couldn't even get 50 bucks for it. Price dropped to 0 and it sat there on give it away for a couple of weeks then off it went to the recyclers.
It is a flash script running on an old Blackberry z10 phone. Reads the time of the network and displays it out the HDMI port. HDMI to video, then it hits a channel 17 mid band cable modulator and the little TV is just tuned to the frequency. If you would like to see it I will show it of. Looks funny because the battery is shot and puffed up so I took the protection circuit out o the original cell, attached it to (currently) an 18650 cell, and fired it to the terminals on the phone. Circuit is hot glued into the back of the phone with the cell external. (charger keeps it charged) I just use it for the clock display as it is always accurate. I have different scripts I can run. Just a little bit o flash code. This works on Blackberry 10 because the original version of the BB10 OS supported flash directly. Old playbook will do it as well. Sure there are clock apps for android but these always have the silly soft button on the display, and I don't know of many android devices that have an hdmi out port on them that the blackberries did. Z10, Z30 and Playbook did. They also can run android apps, which is something that many people did not know.
@@12voltvids And a very helpful one at that. It so far has tracked plenty of CD players, speed-monitored tape decks, and even checked the pulses in a VCR. I'm hooked. Speaking of electronics, my parents' shed has quite a bit of a treasure trove inside. Dug through and found a bunch of old motherboards and graphics cards. The notable card in that pile was the 3dfx Voodoo2. Nice card to have around, indeed.
@@12voltvids You obviously know what you're doing! I was worried about screws tho, lol I'm just happy to watch your excellent logic/troubleshooting regimen- keep the great videos coming sir!
I have a subwoofer amp that had the negative and positive touch each other while getting a signal and they welded together. now the amp is just pushing the speaker up and the coil will start to smell any way I can fix this the model is a Velodyne SPL-1000.
I got a bose wave radio that has DC on the speakers....I changed the amp module , and it still has DC on the speakers ? funny if you plug in speakers to the variable outputs... clear as a bell but low volume...ready to trash it...I thought tin whiskers were only a germanium problem...
I thought that thyristers were the only thing used to deal with heat in a circuit, not transistors or diodes. I never knew about tin wiskers before. I had a lot of schooling but never learned a lot of what you go over.
I meant thermistor, those resistors that change resistance depending on temperature. I thought that that was the only thing that was used for temp. control in circuits. Frank Frank Reiser Video/Audio Service. Now, I'll take a break from you, teacher, and repair a CD player that does not repeat a song when you press the button repeat. An easy fix. I hope it is not the chip.@@12voltvids
@@frankreiserm.s.8039 Thermistor's came in 2 varieties, PTC and NTC. PTC resistance was low when cold, and NTC the opposite. Started higher in resistance and went lower as they heated. Positive temperature coefficent were generally used in degauss circuits and Negative tempature in soft start circuits to control inrush, this allowed big capacitors to charge up slowly. Some early amplifier designs used a thermistor to adjust bias current as the amplifier warmed, but most modern designs just use a basic silicon transistor for this task, as thermal characteristics of silicon is much more linear and predictable in a transistor than a thermistor which can be off by as much as 20% or more, and they drift pretty much every time they heat and cool. A silicon transistor or silicon diode junction is stable. many times they use a transistor with the E and C junctions shorted and just use the E-B and C-B junctions in parallel as 2 diodes.
@@12voltvids How do you know all of this? Are you also an electrical engineer? Did you study engineering? I studied (audited a one-year introductory course at India Institute of Technology, not electrical engineering, but power engineering (power plants, power transmission lines, substations, etc.). It was filled with calculus, which I stink at, but I memorized all of the equations. One of the most interesting things was I learned the power lines share resistance, reactance, capacitance, inductance, susceptance between them, even though they run in parallel, and that these traits become significant over long distances and have to be adjusted at major substations. I also watch videos by TD Power Skills on TH-cam which is lineman training. As you know, Westinghouse figured out that AC can be transmitted over long distances, not DC. However, I watched videos where China transmits DC at 600,000 volts over long distances. How, I have no idea; it goes against everything that I learned. I actually can't believe it.
I did study engineering, but the majority of my skillset came from on job training. In the 20 years I worked in the business I went to many courses put on by the manufactures. As far as transmission goes DC is used for high voltage long distance transmission because it has less loss over long distance. The problem is it has to be converted back to ac, so conversion losses have to be factored in. For shorter hauls it is not efficient, but for long distance it is still favored as the losses are much less.
Maybe it is time that the naughty transistors were replaced with new transistors that don't exhibit the same problem if they are PNP then BC212L if NPN then BC182L.
Random Electronics and Displays It comes from the metal and interaction with all kinds of things oxygen being one but even without air it can happen and after all these years they still can't pinpoint exactly what causes it. Galaxie 4 satellite was taken out by a short circuit suspected by tin whiskers in space.
@@12voltvids they are a few theories out there. Someone will figure it out one day. I know it's been a bit of a concern with satellites. They realised that tin whiskers were growing on circuit board after having put satellites in orbit.
Capacitors block DC from getting from one stage to the next. Some early solid state amps used just npn transistors and an output cap to block DC. Push pull couple the outputs directly to the speakers.
@@frankreiserm.s.8039 Not working, tonight. My daughter just went through a break up, and I was quite tired of listening to her in bitch mode tonight, so I am hiding. Wouldn't be able to film anything tonight because the walls are not that thick, and the curse words would be drawing a constant BEEP in the sound track.
I found the Manual for your Tektronix scope I can send you - It's for the 2465B & 2467B Oscilloscopes - Either by Print copy or Email you the PDF which is a 32.2MB file let me know if you can use it
Interesting, I have seen tin whiskers cause problems with old Germanium transistors but never in the way you showed! I just learned something today!
Yea once you get rid of these tin whiskers, spray the board with silicone lubricant, also tinning the leads of the transistors cures the problem permanently
Interesting phenomenon, electronic stalactites! Definitely one to look out for in future!
You know electricity always tries the path of least resistance
@@Synthematix just like myself! ;-)
Nice find/ fix Dave. The tin whiskers was something I heard about the electronics from NASA which developed from solder particles thus TIN which seemed to ionize with voltage and reattach themselves on a nearby metallic conductor or solder joint. I think changing the cause - tin / lead solder, was why solder content was changed. Do you think a clean nylon paint brush and compressor would help eliminate them ?
Tin whiskers are an allotrope of tin that has a very loose structure, they are not caused by oxidisation; search for Cody's video about tin pest to see what it looks like on a larger scale. I'm aware it's an issue on lead free circuits because the lead helped prevent the whiskers from forming, so I'm surprised to see it on such an old piece of equipment.
Beautiful, well done videos. Clarity and diction of narrative rivals that of best professionals.
I agree... really get tired of mumbling, whispering and guys who can't form a sentence, or use a tripod.
Tin Whiskers - the name of my next rock band!
Annoying neighbours, yap yap yap ... sometimes you may wonder if they ever shut up.
Tin whiskers - a big problem with some vintage tube equipment.
But you sorted the fault out quickly by de-whiskering the transistors and got that receiver working fully once again - winner.
I had several Loudmouth neighbors move in accross the street. always know when they are up and about! she bellows like a bull buffalo when she calls her dog, laughs like a hiyena when she hears a joke, waddles like a penguin when she walks to the car. and I always know when their brats and them exit the car by the resounding slamming of the doors. I call them the "Slam-Bangers"
I learned something today. Never heard of Tin Whiskers. Very Interesting
Hello Again
I Have to reiterate I love watching you repair electronic devices but I also like watching you repair electrical stuff as well Your videos are always interesting and very informative Also I have to say it again I love your MGM CAT
This vdo helped me immensely.thankyou very much.
I replaced my output caps on my sansui 777D . And a few transistors . But my speakers started a slow rhythmic in and out move. Im gonna follow the checkups like you have done in this vdo. Hopefully i wont need a tech..thanks alot .
Very impressed you caught tin whiskers like that. I likely would have missed such a fault.
When you have been working on electronics for more than 35 years you get to know what to look for.
Plastikote Circuitboard lacquer on those transistors should stop the whisker issue
Amps with high negative feedback are quicker to trace with a scope as the stage not working will have a serious voltage shift that is not being conducted to the next stage.
Nice looking receiver. Those always looked better in my opinion.
Would putting plastic tubing on the transistor leads prevent tin whiskers? Just an idea.
Or maybe Gillette has an idea.
Tin whiskers !, learnt something new today. Great watching your videos, thanks from India.
Doesn't know the words... 😂 But seriously folks, always enjoy your solid troubleshooting and your narration of the process you go through! 🇨🇦
Sounds like some folks besides you were having fun :).
It's humming because it does't know the words...ROFL!!!
Yeah, got me also. Too easy went right with it. Lol
better then buzzing cause there might be a beehive inside
Many Thanks for doing this vid I have the same problem with voltage on a speaker output with my amp. Thank you .
When I was working we had some very clever people trying to figure out how to stop tin whiskers with not much success. I guess they will remain one of those things on the check list.
Thats why they used glues
Yes I remember them trying various glues and coatings. All caused other issues but a lot of manufacturers used them.
Hi,Joe from Nairobi Kenya.big fan of your channel.so last week got myself a technics SU-X302 amp. Worked well at first , but when i got home n hooked it up to my speakers, played for about 2 minutes then went mute.Took it apart, tried fixing any possible cold joints,put it back together , worked for another minute or so then cut out....i then got into the input board and recapped it all,still no sound. could it be a burnt IC?It uses SVI 3102C chip.I dont suspect the chip since from time to time it does give sound.I have tried checking all voltages around most of the transistors and chips ,everything checks out as per the service manual.I am really puzzled.please help
Bias at drive output transistors are leak current between e-b-c pins.
Hi, would be nice if you would in the start of each repair to show the unit in detail i.e front view at lower angle.
That's a great tip, I've never heard of tin whiskers before.
I have a Hitachi HA-6 at home belonging to a friend with a whopping 53V DC at both A and B, L and R outputs and I really have no idea where to start.
Crazy shit. How the voltage can jump the legs of the transistors through those fuzzies is fascinating. If it was an amp I was restoring, I'd probably replace those transistors (and caps) altogether, but to just get it back up and running, that's a great fix.
Electone_Guy
Why change perfectly good transistors and caps just for the sake of changing them? Most caps will never fail nor will transistors unless they are either defective in manufacturing and if that was the case they would have failed years ago. Or they are overloaded. Solid state devices that have been properly manufactures rarely fail. The changes of getting a cheap knock off and having that part fail are greater then the original. Some of the early transistors were noisy, but if they are functional just leave em alone. Same for caps. With electrolytic only the ones with the big ripple are the ones getting a workout. The small coupling caps are not under stress and unless they were damaged during assembly they will likely be ok. These were from before they went to water based electrolytic. Dont believe me? Pull some and measure them. You will be surprised. Caps are the most likely component to fail this is true but it is certain caps. Ones involved in high current and high frequency. Switch mode power supplies, vertical ramp circuit in sweep circuits.
I've been doing this for 35 years and I have never shotgunned a piece of equipment just because i could. Besides costing the client much more, which likely will tip the scale between repair or replace, you also run the risk that the new caps will be of inferior quality to the originals and in audio equipment this can completely change the sound.
Oh, I agree with you. Some people I do work for just want everything changed. Personally, when I do a restoration, I usually change out all the power supply caps whether they need it or not and I will replace caps in the audio path with "audio grade caps". Yeah, it's probably a load of bull, but it just a hobby. I really like the Nichicon UPW caps for power supply work and Nichicon UKL low-leakage for those old orange coloured caps. And if you get a piece of equipment from NAD, they are usually loaded with horrible Chinese/Taiwanese caps that do fail.
Preventative maintenance, capacitors are shit, always have been, number one failure part in all old electronics. also capacitor technology has come a long long way since the 70s, when they fail they can do more damage, its easier to just change them and not fuck about even testing them.
Right, and if you have someone that says knock yourself out change all the caps here is 500.00.
But they don't. They say can you fix my stereo for 50 bucks. And for that they get the problem fixed and nothing more.
I'll chance them all out on tube radios, because those ones do fail, but the ones made in the 70's and 80's were pretty good. They don't fail as often as you think. The biggest problem was and still is bad solder connections.
@@12voltvids yes, I come across plenty dry joints, some amps Ive done were full of them! I bought a technics M10 cassette deck nice and cheap, and the thing sounded odd - like a fuzzy distortion in the audio. For some reason most of its caps were leaking from thier pins, so I had to do a full recap which was tedious work. Only did it as I love the old hifi gear, anyway did that, cleaned all switches, new belts ect and now it's a lovely working deck. I got another M10 but a black one, I replaced the power caps only in that one as the other caps seemed ok. Here's a question: the black one is from Germany with '220v' input, the other one is 240v. So, why would one deck need full recap and not the other? Maybe stored in different temperatures?
Unbelievable! I never knew about tin whiskers!!! Duuuuude! :)
Thank you for this vid. I learned a lot again.
Love the "messy" workbench, resembles mine. I know where everything is, but others thick it is chaos.
Drives a few crazy that they feel the need to comment. Most find themself on the ban list.
Its the simple minds, those with the lower IQs that need everything put in it's place. Geniuses don't require this, as they can remember exactly where they left something. Ever see Albert Einsteins desk?
"Does keeping a messy desk make you more creative?
Working at a messy desk may actually help you think more creatively, according to a new scientific study. Scientists found that being surrounded by clutter can promote creative thinking and stimulate new ideas.Aug 6, 2013"
Orderly choas is when we know where everything is.
Bit OT, but I'd like some advice: have a Sony STR-GX47ES receiver, bought cheap, but it has a problem w/ the left channel. Upon, a cold power-up, if the volume isn't set to about the 10 o'clock position (roughly one-third up), there's no left channel. If I power-up w/ it set to that "sweet-spot", the left kicks in, right after the relay click. From then on both channels will work fine.
As for troubleshooting, I've tried cleaning the volume pot & reseating the ribbon cables that connect the volume board to the main board, but no dice. Any ideas?
Madness832
Many Sony receivers suffer the cracked solder connection on voltage amplifier ic. I did a video on a Sony receiver a few years ago.
I had since solved this problem -- a dirty speaker selection switch. But now I've recently acquired a STR-GX49ES, identical to the 47 (adds a bit more RMS power). It's had the same problem, except it was the right channel not working.
sanyo I had was full of sound , 2piesc stack with tape deck , pitty about the wood on them all but they were quallity all round
I suspect there will be more Tin whiskers faults in Circuit boards with lead free solder .
This is why they put a conformal coating on new boards to seal the connections and prevent this.
No its not the solder its the metal they used for the pins
In this case yes, because there is no solder around them, but whiskers grow on solder too.
Its the type of metals they used in the old days, especially mild steels that degrade with age, that along with atmospheric conditions contributes towards it. There are also a lot of alloys that are really good at turning into a sandpaper texture. Only high quality metals can be connected this close electrically without problems, which is why circuit boards are copper not steel (nothing to do with conductivity as silver would be the best anyway) and why new modern electronics parts are superior both with tolerances and specs/materials. remember in the 60s/70s all electronics mags touted their capacitors as being the best, but then there was no way of knowing this until modern technology arrived.
13:03 is that a Tantalum cap behind the transistor (it touched it when you bent the transistor over)? If so, I have seen from some of my other subscriptions that the green Tantalum caps are starting to fail short in older PC computer equipment. Might be worth keeping an eye on any tantalums in stuff you get in?
I believe that was a ceramic cap.
Tantalum caps can fail but they usually do so with a "bang"
Ah cool, I guess the protection in PC power supplies is just too sensitive to clear the short lol.
we both had the same diagnosis lol output transistor if not then the drivers!
pioneer vsx-921 model amplifier output 56 volt DC reading Do you know why?
thanks
Where can I find those magnifying glasses?
Very good video, as always.
Could you give me some advice to open my own repair shop at home?
I do not always have equipment to repair and I would like to know if you buy some equipment online that does not work to repair and sell.
Thank you very much and greetings!
I don't buy equipment. I take donations of old equipment which I fix and sell, but more o it is stuff that is brought to me or repair. I ran a repair shop locally for 20 years, and have been doing repairs out o my house in the 15 since I let the business. 35 years in the electronics repair business.
Kinda looks like an Akai receiver I used to have, looking at the knobs and knob layour.
Just a question when you find the whiskers and scrape them off shouldnt follow up with a good contact cleaner and flush the transistors and control boards? I would of flushed the boards before reinstalling them. I am no expert just a observation
Not necessary. They will grow back regardless. Flushing with cleaner can introduce more issues. We can't get the good cleaner that evaporates with zero residue anymore. Even 99% ipa has 1% water and that will leave minute residue if any minerals in it. Besides unless it is in a vacuum contaminants from the air will get to it. Better to leave the components alone. This stuff is so old it really shouldn't be working.
@@12voltvids Oh okay thanks for the reply and letting me know
Ooow i didn't get a notification for this one :-(.
And i only thought the Af117's got tin whiskers, but on the inside.
Nice old transistor P.A, i thought the outputs were germanium untill you tested them.
One happy owner :-D
learned alot from you..thanks a lot...👍👍👍
That was an interesting problem indeed. Have learnt something new "Tin Whiskers" is it??
That's something else, never would have thought of. I Never heard about that one either. For some reason I didn't get the link in my e-mail on this Vid?? I seen that someone else had the same problem, wonder why. Oh yeah forgot to ask, how pleased are you with your cordless screwdriver now that you have used it for a while?
I don't know what is up with youtube these days. I don't get half my notifications either. I am supposed to get an email of all comments and I get about 1 out of every 10 if I am lucky.
You used a dental pick to remove the tin whiskers. I wonder if they can be blasted off using a tuner wash or some spray like that?
Here’s a link for the manual for the scope. www.tek.com/manual/2465-operators-manual
Pretty cool sleuthing skills there. Never would have thought of that. But, I just always cringe when I see someone using a power screwdriver around fragile components. Even in the hands of a pro it is just too easy to have it slip and run across a ceramic cap, zener diode or a transistor. Plus, they strip small phillips screws. I mean if its my own gear and I don't really care I guess that's one thing but someone else's receiver? Nope. Problem is that a lot of rookies watch these vids and think that's the way to go. Just use a normal screwdriver, take your time and be careful. They don't make this stuff anymore. Thanks for the video. Good one!
Well this was mine and this will make you cry. I recycled it after i was done with it. Had it up for sale for months. Couldn't even get 50 bucks for it. Price dropped to 0 and it sat there on give it away for a couple of weeks then off it went to the recyclers.
A case of electronic "5 o'clock shadow". "Schick" to the rescue.
Got an Akai amp with same fault, yet i don't see tin whiskers on preamp transistors, ( Ialready replaced Amp IC's), still has the fault
I usually called that transistor a bias transistor the hotter it gets the current go up yes indeed
What causes the tin whiskers?
Mark Anderson
That is the 60000 question. Nobody really knows exactly what caused it.
What do you use to generate the clock for that TV?
It is a flash script running on an old Blackberry z10 phone. Reads the time of the network and displays it out the HDMI port. HDMI to video, then it hits a channel 17 mid band cable modulator and the little TV is just tuned to the frequency. If you would like to see it I will show it of. Looks funny because the battery is shot and puffed up so I took the protection circuit out o the original cell, attached it to (currently) an 18650 cell, and fired it to the terminals on the phone. Circuit is hot glued into the back of the phone with the cell external. (charger keeps it charged) I just use it for the clock display as it is always accurate. I have different scripts I can run. Just a little bit o flash code. This works on Blackberry 10 because the original version of the BB10 OS supported flash directly. Old playbook will do it as well. Sure there are clock apps for android but these always have the silly soft button on the display, and I don't know of many android devices that have an hdmi out port on them that the blackberries did. Z10, Z30 and Playbook did. They also can run android apps, which is something that many people did not know.
you didnt burn your speaker out with that voltage going in to it ?
roger willams
It would have if I left it running in that state.
Tektronix scopes are awesome.
you got a new scope very nice
He's had it for months now. Just recently he figured out the voltage display. Shame that it doesn't show on AC as well as DC, though.
Colton Rushton
It was a donation from a viewer.
@@12voltvids And a very helpful one at that. It so far has tracked plenty of CD players, speed-monitored tape decks, and even checked the pulses in a VCR. I'm hooked. Speaking of electronics, my parents' shed has quite a bit of a treasure trove inside. Dug through and found a bunch of old motherboards and graphics cards. The notable card in that pile was the 3dfx Voodoo2. Nice card to have around, indeed.
thanks for this one ( and for all the other vids) my appreciation via paypal greetings
Thanks
What's all that noise at 7:50
Sal khan
That would be the neighbors. They were having a party and making a bunch of noise.
@@12voltvids wankers
Yeah I’ve seen tin whiskers play havoc before on electronics & some vintage tv’s.
tin Wiskas? Playing Havoc? what group is that??
Someone engraved their SIN number on the bottom of the front panel for theft?
R V
At some time someone did.
You're a helluva tech but I wish you would turn down the torque monster clutch on your new driver! Love your attention to detail-true pro
Its not set that high, won't damage screws. I can actually stop that unit with my hand.
@@12voltvids You obviously know what you're doing! I was worried about screws tho, lol I'm just happy to watch your excellent logic/troubleshooting regimen- keep the great videos coming sir!
but is not really zero is 15mV....
also a problem?
no problem
That Sanyo DCX4000 Looks exactly like my Marantz
I have a subwoofer amp that had the negative and positive touch each other while getting a signal and they welded together. now the amp is just pushing the speaker up and the coil will start to smell any way I can fix this the model is a Velodyne SPL-1000.
So you have blown the amp, and if the speaker was smoking you have cooked that too.
Is that fixable or is the amp toast. By the way i love your channel so far.
@@Speakertweaker-tp4em
If the parts are available it is probably fixable but you will need a new speaker as well.
I got a bose wave radio that has DC on the speakers....I changed the amp module , and it still has DC on the speakers ? funny if you plug in speakers to the variable outputs... clear as a bell but low volume...ready to trash it...I thought tin whiskers were only a germanium problem...
Tin whiskers are a solder problem. They have been problematic longer than transistors. Lots of problems caused by them in tube gear too.
I thought that thyristers were the only thing used to deal with heat in a circuit, not transistors or diodes. I never knew about tin wiskers before. I had a lot of schooling but never learned a lot of what you go over.
Thyrister is the same as an scr.
I meant thermistor, those resistors that change resistance depending on temperature. I thought that that was the only thing that was used for temp. control in circuits. Frank Frank Reiser Video/Audio Service. Now, I'll take a break from you, teacher, and repair a CD player that does not repeat a song when you press the button repeat. An easy fix. I hope it is not the chip.@@12voltvids
@@frankreiserm.s.8039
Thermistor's came in 2 varieties, PTC and NTC. PTC resistance was low when cold, and NTC the opposite. Started higher in resistance and went lower as they heated. Positive temperature coefficent were generally used in degauss circuits and Negative tempature in soft start circuits to control inrush, this allowed big capacitors to charge up slowly.
Some early amplifier designs used a thermistor to adjust bias current as the amplifier warmed, but most modern designs just use a basic silicon transistor
for this task, as thermal characteristics of silicon is much more linear and predictable in a transistor than a thermistor which can be off by as much as 20% or more, and they drift pretty much every time they heat and cool. A silicon transistor or silicon diode junction is stable. many times they use a transistor with the E and C junctions shorted and just use the E-B and C-B junctions in parallel as 2 diodes.
@@12voltvids How do you know all of this? Are you also an electrical engineer? Did you study engineering? I studied (audited a one-year introductory course at India Institute of Technology, not electrical engineering, but power engineering (power plants, power transmission lines, substations, etc.). It was filled with calculus, which I stink at, but I memorized all of the equations. One of the most interesting things was I learned the power lines share resistance, reactance, capacitance, inductance, susceptance between them, even though they run in parallel, and that these traits become significant over long distances and have to be adjusted at major substations. I also watch videos by TD Power Skills on TH-cam which is lineman training. As you know, Westinghouse figured out that AC can be transmitted over long distances, not DC. However, I watched videos where China transmits DC at 600,000 volts over long distances. How, I have no idea; it goes against everything that I learned. I actually can't believe it.
I did study engineering, but the majority of my skillset came from on job training. In the 20 years I worked in the business I went to many courses put on by the manufactures.
As far as transmission goes DC is used for high voltage long distance transmission because it has less loss over long distance. The problem is it has to be converted back to ac, so conversion losses have to be factored in. For shorter hauls it is not efficient, but for long distance it is still favored as the losses are much less.
Maybe it is time that the naughty transistors were replaced with new transistors that don't exhibit the same problem if they are PNP then BC212L if NPN then BC182L.
Indeed, that would erase the problem from existence altogether. Would allow the machine to operate more reliably for sure.
Tin whiskers are actually tin crystals, coming from the solder and component's legs playing, atoms creeping around.
Random Electronics and Displays
It comes from the metal and interaction with all kinds of things oxygen being one but even without air it can happen and after all these years they still can't pinpoint exactly what causes it.
Galaxie 4 satellite was taken out by a short circuit suspected by tin whiskers in space.
@@12voltvids they are a few theories out there. Someone will figure it out one day.
I know it's been a bit of a concern with satellites. They realised that tin whiskers were growing on circuit board after having put satellites in orbit.
I gave up on stereo equipment when my costly speakers fell apart because the foam webbing turned to jelly
+jim halcom - Happens to most hi-fi speakers sooner or later. That bad foam can be replaced!
But I thought that it was capacitors that prevented DC from going to a speaker, not a transistor.
Frank
Frank Reiser Video/Audio Service
Capacitors block DC from getting from one stage to the next. Some early solid state amps used just npn transistors and an output cap to block DC. Push pull couple the outputs directly to the speakers.
@@12voltvids Thank you. You seem to work late.
@@12voltvids Thanks.
@@frankreiserm.s.8039
Not working, tonight. My daughter just went through a break up, and I was quite tired of listening to her in bitch mode tonight, so I am hiding. Wouldn't be able to film anything tonight because the walls are not that thick, and the curse words would be drawing a constant BEEP in the sound track.
Where in Canuckistan are you located?
The best part
@@12voltvids I live in Miramichi,also :)
Tin wiskers . Most were not aware of this fault . Not because of oxidation ,being non conductive.
good harmonica mike
At last... electric screwdirver... ;-)
A previous video of Dave's shows off the screwdriver. Yes, he recently acquired it, and yes, it's useful for repairs like this...
I think it is a static build up of dust
daza Smit
Affects satellites in space. Those are assembled in clean rooms and there is no oxygen up there but it still Happens.
I found the Manual for your Tektronix scope I can send you - It's for the 2465B & 2467B Oscilloscopes - Either by Print copy or Email you the PDF which is a 32.2MB file let me know if you can use it
2sd438 Old tr pin Oxidation
Generate random noise
Good job sir.......
Thank you this is great!
I have a manual ok
A beautiefull receiver i have also the Sanyo dcx 4000L
Hope u didnt charge him for parts!!
What parts
that's a useless loudspeaker protection fuse...
Ya think
Yea useless, then some asshole fits a 5 amp fuse into a 2amp socket then wonders why the whole amplifier circuit board gets destroyed
❤❤❤❤.
Your kids or maybe neighbors are being ornery and loud, ruining your videos ;-) Must be party day!
His kids at this point are grown-ups.
😀😀😀😀😀😀
fake repair