SNES w/ dead controller ports -- appears to be something wrong with the main board??

Just picked up another SNES today..This one has perfect A/V and everything seems good...except I can't get the damn controllers to work. I'm using a verified working controller and I've tried three different controller ports from different systems and nothing works. I know those ports worked, at least at one point.

I tried cleaning the ribbon cable input on this board but I'm still having no luck.

Is there something on the board itself I should check that might indicate if it's hopeless or not?

Thanks,
-Jordan

 

Just as a follow-up, the power light DOES come on and everything else with the unit seems to work just fine. Just no controller response.

I tried--in addition to swapping out the entire controller board three times--multiple known working controllers as well as a working super scope on the player 2 port. Nothing at all.

I can only assume there's something wrong with some chip on the board, but which one should I look at? Everything APPEARS fine with no obvious burn marks or anything like that. This one has be really confused.

Anyone have any suggestions?

Thanks,
-Jordan

 

Try this, and if nothing else the CPU could be bad.

 

I had a problem where pressing one of the letter buttons always triggered a d-pad button, I always suspected a failed IC chip, in my case I also tested the circuit up to the IC and found nothing wrong.

 

Haven't really had much time to do anything with this lately. I did power up the system last night with my AsciiPad and somehow the controller worked (I think?) but only for a few button presses. The game loaded, hit the title screen, and then the game (Super Turrican) started. From there, nothing, and I couldn't get the system to load the game in similar fashion again. Just title screen+demo afterward. Very odd...

 

All of the controller data are carried over just one wire so if a few buttons are working, either you got bad controller or a flaky SNES that has trouble decoding controller data for some reason. Did you try the same controller on a good SNES system to make sure it works?

 

This is my main controller which I use almost exclusively on my other system.

I'm assuming the controller worked once on this other system--kind of--since the game actually started but I was unable to reproduce the behavior. It wouldn't respond to anything after that.

This console is beyond flaky.

 

Are the controller ports connected the mainboard? They are connected by a ribbon cable.

 

Yes, the ports are connected to the main board. The on/off indicator light is coming on so I know the ports are getting power from the main board. I've tried three sets of controller ports, all with the same result.