N64 Display Issue flickers through rgb/orange/purple/b&w!

Hey Everyone,

Got two N64 consoles in lot of faulty stuff and one of them is being a pain. when I first tested it the AV port on the back was a little iffy, if you wiggled the cable you could sometimes force it to change colours. I re-soldered the entire socket to the motherboard, and tested it again, still nothing. I've stripped it down, rewired again, checked the pins in the socket and tried multiple cables, it all seems fine. I cannot figure out why it's switching colours like this :/

I can only find issues with no image at all, not seen any documented cases of a colour bias (i.e red instead of grey) I have cleaned the cart slot and the expansion slot too, just in case.

Writing this I feel like the obvious answer is to try it with a different socket, which I would do but I don't have any spares. :/ just wondering if there's any other suggestions or if anyone has experienced this before I start looking elsewhere for a replacement socket/wiring it for RCA.

I'm probably going about this completely the wrong way, but I haven't had to deal with N64 wiring and schematics yet so any help would be appreciated.

Thanks

 

tried a different cartridge slot too, still no change. Anyone have any clues?