/vr/ - Retro Games

hey there
I have this old SNES I got from a local game store about 2 years ago, and it has worked perfectly up until now. I just picked up Mario RPG, popped it in and the sound is shit. Only a few sound effects and like half of the music come through, and then there's some bad sound effects happening when they shouldn't.

1) It isn't the game, as I found this happens on other games that didn't previously have this problem
2) It's not the cord, I tested it on my N64 and it's fine, I even tried a new one as well
3) It isn't the AV output, because it happens on the coax output as well
4) I've cleaned up the board inside to the best of my ability and cleaned the contacts as best I could, still nothing

Has anyone else had this problem, or could provide any insight? I'd really like to get this thing up and running. Google didn't help a whole lot.

I did notice a few missing parts, but I don't think they're crucial as it has worked fine for the past 2 years. It's a newer model of the SNES, so I assume they just removed some parts that weren't completely necessary. Either that or the guy before me decided that those parts needed to go.

I'm attaching some pictures of the board. Thanks guys