Just built one of these and they are beautiful! A bonafide PITA to make but the end result is so worth it.
There are a couple of items that need to be mentioned when I was working out some issues with grips03. In addition to the instuctions on posts 86 and 89, there is a correction and a couple of items of note:
-on the IC pinouts diagram, it said to wire LEFT (the direction, not the button) to ground. This is not necessary. It will already be terminated at ground. Just wire that pin to L on the mini PCB.
-when wiring the Left Button (or Y on the Famicom NTT), wire the IC pin to the mini PCB (A). Then wire the drill hole (red hollow circle in the images - scratch off solder mask on the front of the controller board and solder there in the area isolated by the cuts) to the ground (black hollow box) on the backside of the controller board.
-if removing the ICs compromised any of the pins, you can wire to the holes on the board that correspond to the button/direction you're working with. You may have to follow some traces to find out where. Again, scratch off the solder mask to expose the copper and solder there.
Thanks grips! You saved my wrist and forearm!
Pardon the thread necromancy but this is the most relevant place for this IMHO.