Weird Problem With Japanese Controller

[tigertopher]

I've got a weird problem with my Japanese Saturn controller. Some of its buttons work just fine, but others only work if I press them while simultaneously pressing up, down, left or right on the D-pad. What could be causing this? Is this something that can be fixed, or am I going to need to get myself a new controller?

[caseh]

Open the pad up:

Clean the black carbon pads (rub them against paper if shiny)
Clean the contacts on the PCB (use IPA or something similar)

May help, has worked on several pads for me in the past.

[tigertopher]

I've already opened up the controller and cleaned its insides more than once. It hasn't helped at all.

[zyrobs]

One of the pin contacts is broken. Which buttons don't work normally, XYZR or ABC and Start?

If you are lucky, you can just scrape the gunk off the metal contacts on the connector and get away with it. If you are less lucky, the break is somewhere in the cable and you'd have to replace that entire cable (the pad connector can be pried open but it is difficult to do so without making it look crooked afterwards). If you are really, really unlucky, the IC on the pad is damaged.

[tigertopher]

It's B, C and Start that give me problems.