Mattel Aquarius rolling display

[LopJonreb7]

I have a Mattel Aquarius that I got with some other items some years ago. I've never used one before and don't
know if this has had issues before. Didn't find anything online for this issue either. It's a PAL system.

I composite modded and replaced the voltage regulator before being able to test it on a screen.
The image is badly distorted, with a light border to the right and constantly rolls downwards. There is a
distortion in the audio as well.

I've checked and measured but could have missed something of course. The computer seems otherwise OK, I can write and it beeps.

Is this a video sync issue or is it something else? I tested it on my TV (SCART & RCA), upscaler and a monochrome CRT.

Any hints or ideas?

 

[LopJonreb7]

Followup. I've change the capacitors. Only the 50V capacitors were out of spec, the other ones were fine.

I tried another more generic composite mod which works. The picture is not great, but at least I know the computer is OK.

Either the Aquarius AV adapter doesn't work on this board (PAL Radofin S2) or I've managed to do something wrong on the two I built.