N64 stuck Button problem

[Nukatha]

Hello all!

I've got a problem with on of my N64 controllers. The console always thinks that the 'Z' button is being pressed. So, I took the whole thing apart to give it a look-see. I don't see any shorts anywhere on the little z-button circuit board, or at its connection point with the main board.
When I have the board plugged in without any of the rubber buttons, the console continues to respond as though the 'Z' button is being held down, meaning its not a mechanical issue with the plastic button, or the rubber piece.

Any ideas?

[emu_kidid]

Check around the main IC for shorted legs or remove the sub board for the z-button and see if the issue still occurs

[Nukatha]

I removed the entire z-button sub-board from the primary board, and continue to have the same problem. Since then I re-soldered the z-board back into the PCB and ran a knife all along the border of the z-solder point closest to the IC. I figured that would make sure that there's no short between the two z contacts on main board.

Attached is the best photo I could capture of the thing. You can see my knife scores in a U shape around the left 'Z' contact. (The rest of the buttons continue to operate normally after that, so I didn't damage anything...

So, you said something about looking for shorts around the main IC... Nothing strikes me as obvious around there. any specific pins to look more closely at/ do you see anything in the photo?

(I'll try another camera soon)