Sony CCD-VX3 Image degradation after roughly 5-6 min of use

[Pat85206]

Hello everyone this is my first post. After I finished recapping my Sony CCD-VX3 hi8 camcorder, it worked pretty good. Although after a few tapes worth of recording this issue occurred. I am unsure if it was caused by my recap or not but I would like to see what you guys know. If there are any Sony repair technicians out there, please chime in with what you know.

Symptoms:
Camera is either plugged into a wall adapter converter or battery. Tape side functions flawlessly on startup and even with the issue occurring. Tape playback also works with or without the issue occurring. I begin the test by starting a recording. After monitoring the recording for roughly 5-6 minutes the issue occurs. Autofocus, manual and auto white balance, and all other image controls have no effect on the issue before or after it occurs. The issue seems to "stack" on top of the picture regardless of any of the image effects. The flickering will start with yellow and then add blue and static. This will continue indefinitely. The degradation will manifest and is viewable on the viewfinder and on the video output as well. After powering the camera off but keeping the battery, or removing all power, or switching the camera to "VTR" and waiting 10-15 min to switch back, the picture clears up. The degradation is visible on the tape recording. This problem consistently occurs.

-I will provide a video via a shared google drive link along with two service documents to aid in diagnosis. I appreciate the help guys, I just want this camera to work again!


[Attachment 79041 - Click to enlarge]

https://drive.google.com/drive/folders/1ej1RMRNUJ5KCPxk9uiWtit1QFZge960E?usp=sharing

Solutions I have tried so far:
-Replace thermal paste with pads on what appears to be individual processing units for the 3 CCD sensors
-use a wall source for consistent power.

[dellsam34]

So this happens on the camera side only? What about tape playback?

[Pat85206]

Yep, camera side only. I took it apart again and was checking voltages on the DC/DC board and I noticed one of the 5v rails that runs to what I assume is the image processing side of things is only reading 1.5v, meaning one of my caps is probably the wrong rating.

[pandy]

I would check camera schematics to see if sensors require some bias current - described symptoms looks like some drift in time/temperature (my assumption is that you performed thermal grease replacement correctly).

[Pat85206]

Yep I'm thinking its something to do with timing. Especially since its got low voltage on the 5v rail to Vc-116. I used high quality thermal pad that is usable for computer cpu's off of amazon, its pretty overkill but I though I would ensure it would have no chance of overheating. Still no dice with that. One issue is that the board that's producing the low voltage has no schematic or breakdown in the manual. Its relative F107 does but E107 doesn't. I have another vx3 with the hallmark cap issues just like mine had coming from ebay. Got it for $65 shipped which wasn't to bad for a vx3. I'm going to compare e107 and attempt to swap assemblies and see if it irons itself out.

[pandy]

Nowadays thermal runout can be easily verified with FLIR camera - i bet you can borrow such thing nearby or even try to buy something inexpensive.

If this is thermal problem then freezer in spray will help to detect issue...

[dellsam34]

I would also reflow the chips responsible for the picture processing, Some may warp and lift when they get warm. It is a delicate task though, not everyone can do it.

[Pat85206]

Ok update time. I reapplied and soldered back down the thermal pads and heat shield/grounding shroud on vc-116. The glitching problem is gone, hooray! Now the camera can record clean picture past 5 min. Now I have a new problem though. I have added a new video named "zebra issue.mp4" to the google drive folder showing how about every 15ish seconds past roughly 4-5min, a light rolling zebraing/striping going from the bottom left to the top right of the screen appears. I'll need to test to see when it starts but after it does it stays consistent. Any ideas guys?

Drive url:
https://drive.google.com/drive/folders/1ej1RMRNUJ5KCPxk9uiWtit1QFZge960E?usp=sharing