As you can see, every line seems to be going nuts, resulting in an unstable image. However, this doesn't appear to be affecting the top inch or two of my screen, and if the screen is displaying mostly colors on every line, then there is no problem at all. I can rule out the monitor, the switchbox, and the cable, since all of my other systems are fine and the same cable can be used with my SNES and have no issues. I'm using a gscartsw, and the problem is the same with the sync scrubber enabled or disabled. I'm not sure what source I'm using for sync from the RGB board, but I'm going to assume it was either C-sync or luma. I poked around inside to see if there was an obviously detached wire or bad connection, but fiddling around with all the RGB wiring doesn't seem to affect things. Is this possibly an issue present within the PPU itself?
I have no idea and would appreciate any troubleshooting tips. Thanks in advance!