JVC HR-S6700U

These SMD capacitors are responsible for the lack of HiFi audio. Note how I wrecked the traces on one side of the board..... I have no HiFi audio on the left channel.....20240808_214107.jpg20240814_205315.jpg
I do have a picture now with a poor vertical lock.....again I think the guides are thwacked.....
20240816_175419.jpg
 
WOW! Glad to see that you got something out of it. It was a nice one, but I don’t have any tapes for it. In retrospect, I should have sent an S video cable, didn’t think of it at the time (you probably have one anyway).
 
More progress! The guides are okay. But there's another nasty SMD 3.3 uf 50v capacitor on the bottom of the head drum that is junk. Couldn't get this to track any tape for shit. Swapped out now we're good. This works for many JVC VCRs of this vintage. All the info in this thread is found on YouTube. Now to fix the no HiFi audio on the left channel problem.....20240820_230724.jpg20240820_231145.jpg20240820_231401.jpg
 
I don’t know how much this matters, but I was always hesitant to run rental tapes through that recorder…
 
Everything inside was really pretty clean. It's basically 98% functional. Just the left channel audio being low and distorted. If tested a bunch of capacitors and they all check out, and the broken trace jumpers all ohm out too, so I don't know what's up. I may need a parts unit. I may see about getting a service manual to see how audio is routed/processed
 
interesting thread, thanks for sharing!

some of what you show here might be useful to get some hints to fix my JVC HR-S4700EG which has the power supply which is totally gone, after some capacitors leaked some brown crap and messed it totally (in fact, I am tempted to replace quite everything on it!)
And before getting the power supply problem, I had experienced issues on HiFi audio which might depend on the dying power supply or also by those SMD caps you mentioned... must definitely check those, too.
 
If yours has the board shown in post #3 that's likely the cause of no hifi audio. Those silver SMD caps are bad and leak and ruin traces. There's also one on the bottom of the head drum. If I get everything up and going on this I'll probably recap the power supply as it runs hot
 
mr_rye89 said:
If yours has the board shown in post #3 that's likely the cause of no hifi audio. Those silver SMD caps are bad and leak and ruin traces. There's also one on the bottom of the head drum. If I get everything up and going on this I'll probably recap the power supply as it runs hot
Click to expand...

is that one the actual audio board? mine has it and, looking at the inside, that 6700 looks a lot like my 4700... maybe the basic design is the same and they share a lot of things?

regarding the power supply....
years ago, when I started experiencing issues on HiFi Audio, I had tried to replace the audio CMOS switches chips but nothing changed then I did put it aside...
and trying it again a couple months ago, it was totally dead... then I removed the whole power supply (that metal box above the mechanism) and I tested a couple capacitors (i.e. the 100uF 400V one) and they were dead... also, the bigger brown ELNA capacitors leaked a lot of brown crap which corroded some tracks and, also, that crap seems to also be somewhat conductive.
While trying to check/troubleshoot it after replacing the capacitors, surely something else got broken then I fear I'd need to replace quite some parts.
At the moment, the power supply is still outside the VCR and waiting for the tricky and long work needed to fix it... let's see how it goes.
I am tempted to buy one of those small component tester devices, to be able to check more parts.

Anyways, If yours powers up correctly, I would immediately recap the power supply before risking that those ELNA leak that crap and make a lot of damage... I mean all electrolytic caps in the power supply should be replaced as soon as possible.
 
Okay we have full good HiFi audio in both channels! The parts unit (HR-S5800U) got here, I yanked its audio/riser board, recapped and wrecked the traces similarly to the other one but have audio somehow. I think I'm gonna watch a movie on it tonight......
 
mr_rye89 said:
Weird issue, no chroma (displaying an image without color) on s-video out, was due to some weird corrosion on the main video board.View attachment 83268
No puking capacitors so IDK WTF. A bad repair and a lifted trace later:
View attachment 83270
And we got chroma
View attachment 83271
Click to expand...


A Ruby Red Eraser will take the corrosion off with no damage. Providing there is still some metal to the runs. Then you can re-tin the runs with fresh solder. Or, dump it, you may fight gremlins a long time.....
 
mr_rye89 said:
due to some weird corrosion on the main video board.

View attachment 83268
Click to expand...

on my 4700 power supply PCB, I've found such kind of corrosion (but a lot worse than there!) just in the zone where those brown ELNA capacitors released all that brown crap... maybe someone just replaced some of them just there, for the same reason?
 
I'm not sure, I think something dripped inside. The PC boards in these are crap, almost as bad as the ones in Philco Predictas. You will lift/break a trace if you look at it wrong.

I have yet to pull the power supply, hopefully no brown shit leaking inside it......
 
You must log in or register to reply here.
Back
Top