Panasonic NV-FS 200 (AG-1980) TBC problem

[VR20D]

My Panasonic NV-FS200 (AG-1980) has developed an issue. When I cold start the unit and switch between TBC on/off, I get this strange artifact. It's now become so severe that the problem is permanent.

The main power supply has been refurbished, all capacitors on the TBC board have been replaced, and the soldering looks fine. The head amp has also been serviced. The unit is now at a repair center, but they haven't been able to identify the issue.

Does anyone have any suggestions on where we should look? Any advice would be greatly appreciated.

I've uploaded the video to YT: https://youtu.be/_Nj1H2afmUM

Thanks in advance.!

[lollo]

MIt's now become so severe that the problem is permanent.

Do you mean that the problem is there even if you do not switch between TBC on and TBC off?

[VR20D]

With TBC on, the picture is good (98%). With TBC off, it's bad.

MIt's now become so severe that the problem is permanent.

Do you mean that the problem is there even if you do not switch between TBC on and TBC off?

[lollo]

With TBC on, the picture is good (98%). With TBC off, it's bad.

With all tapes?

[VR20D]

Correct.

With TBC on, the picture is good (98%). With TBC off, it's bad.

With all tapes?

[aramkolt]

Easiest test here would be to swap the TBC card from one from a machine that doesn't have the issue and see if the problem follows that TBC card or not. Since it has to do with TBC switching on/off, would suspect it's due to the TBC card, but you could also try cleaning the switch itself or hard wiring it to off and see if the problem goes away. Could do the same with the power supply of course (swap for known good unit).