JVC HR-S9911U outputs video in black and white?
 

I recently picked up a JVC HR-S9911U to work on capturing some old VHS tapes.

Occasionally when playing back a tape the color appears to drop, and the deck only outputs a black and white signal. This issue seems to be more present when I first powered the unit on and gradually seemed to disappear as the unit warmed up, but still will occasionally only output black and white. Things I've done to diagnose.

* Tapes being played have all been confirmed to work and play in color on a different VHS player
* When outputting only black and white video the system menus are still displayed in color
* I've tried using both s-video and composite video and the problem is present with both
* Sections that playback in black and white will play back in color later when tried again
* The color degradation doesn't seem to be discrete, the saturation seems to fade and slowly to monochrome and then almost fight back to color gradually

I was wondering if anyone else has experienced similar issues with this or other JVC decks, or if there are any recommendations on how I might go about diagnosing.

Thanks

This is most likely an electronic problem with some capacitors either in the power supply or the chroma stage but I can't confirm without proper diagnosing, If you can't do basic troubleshooting I'm afraid that you're going to have to spend few hundred dollars on repairs and few months in the waiting list.
That is the reason why all these equipment is dumped on ebay, it's too damn expensive to repair and not many people know how to fix them.

Another eBay "tested" and "working" deck, I take it? :hmm:
(ie, Not working, laughable pathetic tests.)

An error like this could anywhere.

However, the most likely issue is in the svideo/composite output blocks, or even in the mainboard electronics. The output block is easy enough to fix (on some JVCs), just a swap-out is needed. On other JVCs, resolder work. The mainboard having issues is often a lost cause, as it doesn't really have caps issues (the "easy" fix).

Unlikely heads.

It's not the transport.

If not mere solder work, expect to essentially buy another "for parts" unit (~$200 for this model), or pay somebody to repair it. I might actually be able to repair this, as I have a "for parts" 9911 deck where heads/transport is shot, but mainboard with/and output/input block is assumed fine.

I'm not quite as pessimistic as our friend latreche, but it will require some money + time. Forget about it being cheap or quick, or either.

It was in fact an ebay purchase :P. Though I had read enough of this forum to not expect a perfectly working unit.

An additional data point that may lead to this being a case of user error, is pebcavcr a thing? When testing the s-video and composite connections I noticed that the problem is reproducible when plugging in or removing the composite video cable while the VCR is connected via s-video. For connivence sake when comparing s-video and composite for a tape I left both connections plugged into the vcr and only unplugged from my capture device.

I've done some recapping work on old video game systems, so willing to take on that challenge. More scared of having to do any work on the heads or VCR specific mechanical parts. I'll do some additional testing and see if this was totally user error and if not do some visual diagnostic and capacitor testing on the output blocks.

Thanks for the help and not totally pessimistic outlook. Will update as I learn more.

Unplugged/plugging eventually damaged the input/output block.

PEBCAVCR is a thing! Since the 70s, simply setting the clock. :laugh:
C = couch

But plugging/unplugging comp+svid probably didn't do this. So again, output block. Solder work.

No caps.
No heads.

"clean the heads" is a fix-all touted by people that know nothing about VCRs. The heads only need attention with specific image errors, not a general fixing what ails the deck. That's like taking aspirin for everything, be it broken bones or diarrhea -- dumb!