I've got a few non-working SNES that I'm trying to restore. One is giving me a bit of a headache. It's an early edition model (with SHVC sound module) It boots up, shows picture/sound, but the controller port doesn't work. Simple fix I thought, replace the controller ports from another SNES. The issue continues. (It's not the controller) Specifically, what is happening is that only the B button works, I can't use any arrows, start or other buttons. I've tried multiple controllers, and now two different ports, and the same issues are happening. SOMETIMES if I move the cable around and start mashing buttons, it will start selecting and going back, as if activating two buttons at the same time (for example, SMW goes into Game A, to the one or two player screen, then back to game select) I've tested continuity from each solder point where the ribbon connector connects the port module all the way to the solder points on the mainboard where the connector is, and each one is good. the resistors and capacitors right beside them seem fine, I don't know where to go from here. The issue clearly is on the motherboard, but where? Has anybody experienced this issue? Any solutions that you can think of?