EEVblog 1602 - Sony Amplifier REPAIR ADVENTURE
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- เผยแพร่เมื่อ 10 มิ.ย. 2024
- Repair of a Sony HCD-SBT20B Bluetooth Stereo. What it's like to nail the repair and then, well come-a-gutsa and have to go down the rabbit hole to fix the fix all whilst battling bad design info.
How VFD displays work: • EEVblog 1601 - How VFD...
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Tektronix autopsy: • EEVblog #690 - TDS220 ...
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00:00 - Sony HCD-SBT20B Bluetooth Stereo with a water ingress problem
01:17 - Water isn't that bad actually, even mud.
02:49 - Comically long screwdriver time
04:09 - Vacuum Fluorescent display for all you VFD fanboys
05:10 - Annoying construction
06:14 - Logic level problem? Doesn't seem to be the PSU.
07:57 - Yuck!
09:58 - PCB Cleaning time
12:11 - Did the cleaning work?
13:28 - Hang on, I think I see something...
14:36 - More corrosion
15:21 - Back to measuring voltages on the VFD
17:15 - Handy use of Auto Hold
18:00 - VFD dispaly under the microscope
19:33 - Cathode measurement
20:13 - Anode connection tracing
22:10 - I wouldn't have designed it like this
23:08 - Sanity check
24:32 - What's in the can?
28:16 - Schematic time. Sony service manuals are something else
33:22 - Don't come-a-gutsa on dual diode pinouts
35:16 - Let's power it up on the bench
37:19 - There's something very strange about this...
40:04 - Oh FFS!
42:03 - Now it'll work...
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#ElectronicsCreators #Repair #Sony - วิทยาศาสตร์และเทคโนโลยี
Having been a SONY R&D tech I found this video to be great fun. I was sitting here yelling, "Trace the voltages! Trace the voltages!" Thanks Dave! BTW, I hate those little laminated, printed ribbon cables. They are dirt cheap, and even cheaper to implement, requiring no connectors on the cable ends, but they are all junk, 1 time insertion, no matter what company makes or uses them. Over the years I've fixed numerous pieces of equipment by hand-soldering wires between boards to replace those pieces of crap. They have become the first thing I check in a repair job, even before the supply voltages. They are that bad.
Some brands like Sumitomo usually hold up longer
They are usually failure points in anything that uses them, my wife’s laptop was acting up sometimes powering on and then not responding found the power button attached to the main board with this and one track barely connected.
Yes, they are. I had a brand new Dell notebook back in the day, that always did a hard reset when someone just pushed hard enough on the palm rest next to the touchpad. Turned it to customer service, and it was returned back to me stating that the problem could not be reproduced. I turned it on, and on the first push on the palm rest at the known spot it reset again. So I tackled it myself. Turned out it was the exact same situation as in the video - one trace had separated during manufacturing, and the open end of that trace just had a tenth of a millmetre clearance to chassis ground. When the lid on top was pushed hard enough, it shorted out causing the reset...
Me, too! That's something basic I learned from Louis Rossmann: check the voltage rails first.
Oddly, they are used in military electronics and tend not to be a weak point, but they are printed on polyamide (Kapton) substrates.
Futaba quit the VFD business a few years ago, leaving only Noritake-Itron and some weird China-based companies producing new VFDs. Shame because their reverse-facing modules like the one in this unit look fantastic.
BTW, the ghosting on the display is probably due to some high-impedance short between anode/grid pins, since the anode current is so low, a buildup of crud somewhere would conduct enough to barely light those segments.
Galvanics on the ribbon with the water ingress made the metal strip corrode to the point where the glue let go. Plenty of game console and handhelds videos show the same thing happening.
That !
It's always a treat seeing inside a Sony product and their service manuals. I'd love to get my hands on all the internal documentation that Sony has for design rules and best practices, their modern stuff today really does look like it was designed by the same people who were designing Sony products in the 80's, 90's and 00's, only difference now is it's with modern high density packages with more integration and modern features. Although the VFD really has me thinking maybe the same people have been working at Sony for 50 years, I mean Japan does have the longest average employee retention (12.4 years) of any country.
Same for many other Japanese manufacturers... Panasonic, Epson with which I have personal experience with. 😅
Working at a SONY R&D lab in the USA I had to change a bunch of parameters in our CAD PCB layout package, as well as rebuild all of the padstacks for through-hole components in order to meet the SONY bd design-rules requirements before I did a layout. The bd layout design rules document I got in order to make the mods to our software, even after translation was over 100 pages long. The manufacturing engineers in Otsugi know exactly what they want in a bd layout, and why they want it that way. One of our engineers who had been to Otsugi told me the cubicles of their EE's were half the size of those of their manufacturing engineers.
@@johnwest7993 that sounds really annoying, but if the end result is that good, I guess it is worth it.
Unfortunately there is still a lot of Chinesium in this little unit. From the cheap crappy caps to the CD chipset that appears to be one of those nasty Silan clones of old Toshiba designs. But still, there's a lot more integrity in that than the average cheapo unit for sure.
@@johnwest7993 OMG 100 pages. that explains the bloatware style layouts.
Sorta modern, futaba stopped producing VF displays entirely in 2021, that's a backlit vfd, you're viewing the back of the anodes, painted on the glass, very neat.
It also most likely uses chip-on-glass with an internal driver die and 3.3v logic
Yes, I was going to mention that it appears that it's the bottom. Neat indeed, no mesh or cathode wire to get in the way.
I am wondering if this is the same Futaba that makes the R/C stuff
@@sasmit82 me too!
@@sasmit82 yep. The company has some unusual product lines. Displays, touch interfaces, industrial/hobby radio control systems.
We used to expect service manuals like that, from HP to Motorola, every company was trying to produce the most complete, easy to use service manuals. Companies saw them as a sales plus, something that would help make the sale of equipment to other companies and users, engineer to engineer. It told those who decided what to buy that you knew your stuff. Purchasers would ask the engineers what they thought of a piece of gear before they placed an order, and the engineers would say, "Show me the service manual." Gear was only as good as the service manual. It still is. And almost no one produces a decent service manual. Nowadays, all I want is vintage Heathkit gear, with the manuals. If a component is no longer available it doesn't matter. They included enough info that you can modify a circuit to use a different part.
Yeah, I work in defense and it's the same problem. In the past, there were very detailed Tech Manuals, drawings, and troubleshooting instructions. For us, it's mostly just money and time constraints. Navy gets to decide where money goes, and when things get tight then documentation and other logistic products get cut first. In their mind, it isn't important because most repairs are just dropping in replacement LRUs anyway--they don't really consider some of the knock-on effects, like the operators typically *really don't even understand how the thing works* so they're hopeless if a new unexpected (never before seen) problem arises.
A real beauty mate! We novices learn so much from videos like this, following your logical steps down the rabbit hole and back up again.
LOVE working on older Sony stuff, its a pleasure to see dedication to design and quality of componants.
I hope Mrs EEVblog approved that shot of her at the beginning or you are in big trouble!
I'm always in trouble, so no difference.
Know the feeling.
@@markharwood So do I... dog house anyone?
@@AstrosElectronicsLab Yes, I have had to build my own doghouse! Mind you, it's bigger thn the house and is well equipped with electronics equipment and machine tools.
Blowenfusen und Poppencorken mit Spitzensparken! I like the VFD, indeed a thing of beauty. And the service documentation is damn spot on too. Charge pump and voltage multiplier for -24V, pretty clever. I've seen that used in a voltage multiplier powering a VFD in a Lell PSR drum machine made in the '80s/'90s in the USSR. It was driven from the master clock signal.
Nice fix! Congrats. I feared it was gonna be a complete come-a-gutsa but it came out nicely.
Lol. 😅
i love how dave says The fuse is "Blowen"
Yes, Sony is very creative using the 5vdc buck regulator's switching pin to drive a voltage doubler circuit to -24vdc. 👍👍
I've been doing repair for a job since about a year and things like that happened to me a couple of times: You fix the actual issue and in the meantime you do a mistake. You put it test it and it's not gonna work and you'll look for ages because you broke something and then you have to go all the way back and fix that again. Super frustrating experience!
Cheers Dave and lets not forget Good old Murphy for His input ... Enjoyed the Ride
Best video you've done recently. Well done Dave. Thoroughly educational & enjoyable.
It's fun to find out how it failed, learned something more 👍
This is why I salvage flex cables out of destroyed electronics... they're so fragile that you need a bunch of different kinds to fix stuff :D
VFD very likely because Sony already had that display in the master stock list as a part, and an already existing contract with Futaba for supply of the custom made displays, with a long term arrangement between them. Thus when designing this unit they went with first of all using assemblies they already have design files and firmware in house ready to use, as it is a lot faster to finish a design cycle if the display, CD mechanism (probably actually a DVD mech, as that still reads CD, but having a dual use mech is also a cost saver in inventory, also reusing a common part with possibly only a different clip on face used) and other parts like knobs are already a Sony part number. No need to order special designs (a Sony favourite though) when you can repurpose an existing part instead.
Disassembly the CD mech you need to use the manual release method, and turn the motor to run the drawer open, then press the clips on the side to run it all the way out.
About 2 decades ago, many car CD players added support for playing MP3s from DVDs. Back then, large Flash memory was expensive but writable DVDs were getting cheap.
That feeling when figuring out the problem is quite great, even when watching someone else do it!
That sounded like a very satisfying "Aaaah" at the end. Excellent skills.
Daves repair videos are always exciting!
This was a great video. I have often been frustrated trying to make these measurements using digital scopes. However, your video shows a number of really good strategies. I thank you for posting it. On my HP 8647A, the modulation connector becomes an output when the internal modulation source is used, and this works well for triggering. 73 and thanks again!
I love the generic "LOGO" on the boards were someone obviously meant to put some pretty logo on the silkscreen.
Great one! Lot's of great fault finding techniques here. Top stuff!
4:20 What a gorgeous VFD. Bobby dazzler.
LOL! Full Murphy energy discharge on that one. Gets you each and every time. 😂
Love these repair videos. Always down the rabbit hole and back again. 🤣
fantastic. this video perfectly shows how it is to repair electronics. love it
the surprised face at 36:55
we've all been there 😄
i just love this vacuum fluorescent, they are just beautiful to see, and spread a warm light. in short they are worth the extra dollars.
i hate them. VFDs look cold and stark. ive been adjusting color with orange/yellow plastic film for a warmer glow. long story chopped, its worth the extra cents.
When manufacturing computer (array processor) circuit boards in the '70s, we ran the assembled boards through a dishwasher before final assembly.
Repair…😂 as a kid I took a small tv out of the little canal behind our house (somebody dumpt it) dried it and used it for years. Only a sound problem. One transistor (simple pnp) seems to blow up once in a while. Put a new one in on a footpeach, and replaced it when blowing.
It's always the physical you miss that gets ya! Been there too many times. And you're right, Sony service manuals are AWESOME!
Good job Dave! This was one of your best repairs, even if Murphy didn't help 😅. And yes, Sony service manuals are top notch.
I learn so much about electronics just from watching you troubleshoot stuff, thank you 👍
In my own experience water is practically harmless until it meets up with electricity. Conducting even fairly small amounts of current through water can induce quite the impressive galvanic corrosion and eat away traces and such fairly quickly.
But if a piece of electronics have no power supplied to it, then one can often dunk it in water without any worry what so ever. Other than some components being good at trapping water inside them, be it relays, some switches, and other stuff. This can often lead to unwanted corrosion over time.
Murphy has certainly made a right pin out of you, great job fixing it
I've got one of those. Your schematic lists an MPEG decoder because certain models can play DVDs.
Murphy struck again. Glad you found the issue and fixed it!
Does ribbon cables are a right pain!
Nice repair video.
Good job.
As for the shadow segments not turning off. Make sure the voltage separation between the filaments, the grids and the anodes is correct. Sometimes when the filaments and the grids are to close in voltage they don't cut off properly.
I hate ribbon cables! Good job tracking this one down.
got to love murphy, he keeps you on your toes lol. cool video pleased it works
Love the 1.21GW multimeter!
Yes, I like this. Repair, jelly bean components, tutorials, real electronics
Nice video Dave. I have just replacesed the pushbuttons on exact the same thing that manifested random or no commands.
40:11 - It Was At This Moment He Knew... He Fucked Up!.
I've fixed so many electronics over the years, and I swear those tiny ribbon cables are more delicate than my aunt's fine china collection. One re-insertion, being careful AF, only to discover all the bloody pins have overlapped and shorted together GRR!
You can expose a little bit of the traces on the ribbon cable in an attempt to fix it, however, I would yeet the cable & connector and replace 'em with wires going from the traces on the board to another board.
I love fluorescent displays, they bring some magic to device =)
I love repair videos! 😍
It lookes that pin 5 and 6 of the cabel to the display are still rough which could cause the cable to strip. Perhaps there is still more corrosion on that connector which leads to a dimmed operating mode. With 24V on a pin in humid environment can lead to extra contact corrosion, similar to batteries in bicycle front or back lights.
I think you need to recalibrate your mark 2 eyeball test equipment!!😁😁😁😁
had to say how funny this was... been there myself, spent 6 hours once trying to debug a complex embedded computer system editing source code and uploading firmware to waggle pins to capture an intermittent failure mode. I eventually figured out why it wasn't triggering my scope - I had been editing my backup source code copy and been uploading the original firmware all the time without the pin waggle to my scope :o( From that I created my maxim... believe what your equipment is telling you and not what you think is happening LOL. Credit to technical authors worldwide - good ones are worth their weight in scope probes :o)
What Turd Burglar !! Im working on Fujitsu Heatpump PCB repair as a side jig, I could find a service manual of a older model with diffrent gas ( pre-R32) 90% of the PCB is similar and I could replace few components and make my friends happy.. Thanks Dave you videos have been very influential in past 10 years to me
28:16 Service manual gold from Sony, Bravo. ;)
That VFD is a reverse view type. Normally the filaments are in front, then the grids, then the anodes with the glowing bits are the back and viewed through the grids. This one is backwards, the filaments are the back then the grids, and the glowing bits are on the opposite side of the anodes. The advantage is the display appears to have a higher resolution.
I have a massive Sony AV system that’s about 25 years old and has a dead VFD, it’s very large and complicated but the rest of the system works and can change sources with the function button and remote. I’m going to check the same criteria, cathode power and voltages and hope for the best, there are several nasty ribbon cables too so some deox spray and reseating might not go amiss
Optional board makes sense as only some regions have DAB. No sense in including a DAB decoder in North America!
Ah Quantum connector theory! If you dont look at a connector it will be both connected and not connected until you actually get your eye ball on it!
Amazing! :-) Still: They designed the cable to be pin1 to "not pin1". Weird.
One of my favorite DJs mentioned some people drop drinks on the mixer panel in their studio. This was a reoccurring thing in their studio. Apparently the first question the tech who maintains the mixers asked is "was it a diet drink or sugared drink". If it's a sugared drink they trash the mixer or it's an expensive repair if not they just let it dry out. Yes, people sugar kills!! (mixers) . This is all anecdotal. I tend not to drop drinks on my equipment but I'm pretty sure now I mentioned this it's going to be the next thing I do.
Isn't that mostly because (most) diet sodas aren't sticky though? So they won't gum things up when they dry. Can't imagine diet soda being a less conductive.
@@oliverer3 no clue I can imagine the sugar dries up as a conductive mess. I'm not going to experiment with my mixer any time soon.
30 odd years ago I worked in the TV industry. One afternoon a vision operator knocked his coffee over 4 camera exposure controls. The only thing we could do was taken them out (borrowed a set from another studio) and strip them down and wash them through in a sink. Sugary drinks is a real killer. Once dried and cleaned they worked for many years
Exact same thing happened to me when repairing an amplifier. Damn thing could only be used with a remote, and it didn't come with one. So I had to order a replacement, and it didn't work. Got another, that didn't work either, luckily got a refund. Both of those were aftermarket ones, so eventually I tracked down an original and that didn't work either... decided to do a final inspection before throwing it out of the window, and turns out that the front panel ribbon connector had ONE PIN torn off and bent like that. And according to the manual, it was the pin controlling the front infrared receiver.
Reseated the ribbon not unlike in this video, and it worked fine afterwards. For about a year, until the dodgy Texas Instruments DSP gave away (TI had a chemical spill in their factories and for a good decade all amps using their chips had huge recall issues).
Just seen all the video, Murphi strikes again.
I think that display panel was used in a lot of Sony gear, so at one point the pinouts were correct.
Dave luck is like my luck in servicing 😂
The bit of plastic on the front of the CD tray snaps on to the rest of the CD drive assembly. It is removable and what is catching on the front of the unit causing you trouble. This is how they change the color of the CD Player device to match the rest of the unit without having to make different drives for each color. Manually operate the CD Tray motor so the tray sticks out a bit and you will see it probably slides up and off.
The instructor at iPad rehab always says you don't know you have a component problem until you make sure you don't have a parts problem. Ha ha
For the CD tray. Just apply voltage to the motor and it comes out. Then you can remove the cover easily.
nice one, i see u might have peoblem with psu for vacum display as i did repair recently my DAT 750 with strange extra lightning pathern on display and the problem was zener diode, after replacement the zener then display was perfect and didnt light up extra patherns. have check all components related to display.
Omg I lol so hard at the end
Enjoyed. What phone is that you tested on? I like the more rectangular look of it..
I dread mucking with those flat flex cables and will go to great lengths to avoid having to unseat/reseat them haha
troubleshooting the troubleshooting
How it was still working but dim, if there wasn't any voltage because of the ripped off pin?
Something I think people forget sometimes when something gets left outside and it rains and it gets wet is that not only did it get wet but there may have been a storm and it could have taken a bit of a shock as well.
Can't beat a vacuum fluorescent display! LED and LCD screens needs a backlight and are always too bright. Like bright enough to light up a dark room. Vfd just has a subtle glow.
34:59 it is NOT a pull-down. It's part of a voltage divider to create around 4.0V for the ENable pin
A repair video!!! How many tries did it take? Like 40 videos later.
Conductive brush. I wish I had your till
Any repair tech who hasn't 'introduced' a new fault along the way is either lying to themselves, or has not had much experience :) I can still hear my trainer saying to me " go back over what you have done "
Watch out for the Turd Burglar!! 😂😂
coming to steal ur shit
its usually the ribbon cable!...
..sony schematics are really nice... the PS3 ones are amazing...
Bet that heavy scrubbing brush causes the connector ribbon damage.
it's was fun adventure😅
I think the reason they are using a vacuum fluorescent display is you just can’t get that super crisp color and lines out of an LCD display, they are also really easy to read in the light and the dark. It could also be just an aesthetics thing, the look of the front reminds me of early 2000s Apple products which as we know are all about the look of the thing. Keysight is still using a vacuum fluorescent display in the refreshed version of the 3458A and that’s a $15,000 multimeter where you’d kind of expect a fancy LCD display so idk
You can't get that from an LCD but OLED displays can get pretty close.
this will blast the socks off any good enough for australia party
Maybe you could change that -24V to -30V to brighten the display?
Not sure what that would do to the VFD lifetime though...
That's a super long screw driver for fixing electronics...
Still some leakage to the off segments. Dirt on the chip, print, or at the back of the display. It seems to met that the contacts inside the connector for the ribbon cable is oxidised, and that that could 'scrape off' the contact from the cable when you push it in without taking care..
Dave, make yourself a gift, buy Pomona Electronics 6342 test leads with very sharp points, and gold-plated tips. They are an order of magnitude better at probing such small circuitry.
Yep, having watch Rossmann repair MacBooks I learned that higher voltage lines accelerate corrosion, so not a complete surprise there, looking back of course. It doesn't help that it was hidden from view.
If you actually want to lean anything, watch anyone and anything else, then Rossmann. I don't care if its Teletubbies, you're likely to learn way more actual proper information.
Also, you avoid "Repair Bias" AKA basically if you only repair MacBooks by choice (because they are actually worth repairing 5 years out, actually has a life outside 30 days like unlike everything else does, has resale value, and even continues to work after 2 years), you are going to think MacBook's are trash. Repair bias...
It's funny, he's admitted on numerous occasions admitted he repairs MacBooks because there's no money in repairing anything else. Because with the most expensive Windows machine costing $2 and a sack of potatoes, you just get another if it fails. And honesty who cars if grandmas laptop dies. You just get another
@40:55 Murphy was here 😂😂😂😂😂😂😂😂😂😂
Omg first thing you look at are the pins of the ribbon cables, give me break 45mins for that
Nice one Dave. I recently worked an old clock radio from 1977 with a failed VFP display. No fancy charge pump device, just a separate winding on the output of the transformer to connected to a low current linier PSU to supply 28v DC. Sadly the dedicated secondary winding on the transformer had gone O/C so the unit may end up with the modern Boost circuit instead. Nice informative video Dave, Oh please answer this. Why do you call a mobile phone a shoe phone ?
Watch Get Smart
I believe the display looks kind of off because of leakage between pins on the controller chip. A good clean in ultrasonic bath should fix that :)
I have an onkyo that had the same issue with the ribbon cable that was totally trashed. I have yet to find a replacement, any suggestions.? The ribbon cable seem to come from the flip out control panel. The amp works fine, but the button board controls it all..
Welcome to my world :-)
I had a sony soundbar blow up out of nowhere; i'd say this class b/d type of amplifier stuff is way more sensitive then the traditional mosfet based amps.
They should always use ZIFs for cable attachments!
I'd guess they have a ton of the VFDs left over and it's cheaper to use them then a newer LCD.
Yes, there were times when it was possible to find normal documentation and service manual with disassemble flow manual and troubleshooting procedure... Eh!
Laughing wirh his homour great stuff and repair works.