Denial

Hi everyone, new user here!

I am reviving a VIC-20 REV-E (board 1001006). It is a very early VIC-20, not a VIC-1001.
I have socketed the entire board and replaced:

• All the electrolytic capacitors
• 3 failed glue logic chips
• 3 failed 2114's.

I have tested all other ICs, all functional.
The board is finally alive, but I am now seeing dark bands slowly rolling down the screen (using NTSC composite).
See picture below.

My other VIC-20 with board 324003 with the same VIC 6560 chip, same composite video cable, and same 9VAC 1.5A power supply does not produce this problem.
I have not yet replaced the rectifier and the regulator, as I'd like to first hear some savvy advice from you guys.
Thanks in advance!

Here is the picture. Note that the darker horizontal bands are THE problem and are not caused by my camera.

Tried another PSU? (If they are rolling slowly - most certainly a power problem of some kind)

groepaz wrote: ↑Fri Jan 19, 2024 8:59 am Tried another PSU? (If they are rolling slowly - most certainly a power problem of some kind)

I did not, but I tried the same PSU with another VIC-20 (with a different PCB) and got no such problem.
But maybe different PCB’s have different tolerances to PSU issues?
I wouldn’t mind buying another PSU, as this is a new PSU but only rated at 1.5 Amps.
Any recommendations for a 3 Amps PSU (in the U.S.) ?

It seems to be a defective regulator.