-ipac 4 is installed.
-All grounds have been tested sat (Satisfactory) using an ohm-meter.
-All buttons have been tested sat using an ohm meter.
This means you've checked that the switches work, or that you've checked they work
and are connected to the correct pins on the board? i.e. the P1B1 pin on ipac goes to the player 1 button 1 on the panel?
-Jumpers are set to PS2 and MAME.
-When running win-ipac (And I am in ALT mode), buttons 5 and 6 do NOTHING.
buttons 5 and 6 of which player? it's normal I think for buttons 5 and 6 to be unassigned for players 3 and 4... or maybe that's just mame, and the ipac4 is supposed to be. It's been too long since I programmed my ipac.
Also, they do nothing in what, in mame? or are you testing in Notepad? If you attach a keyboard to the pass-through port on the ipac, you can press ctrl-alt-P on that keyboard and enter a programming utility. Just make sure you have Notepad or some other text editor open when you do. It will "type out" a menu and you make choices with keyboard keys. If you get into that, you can reprogram keys to your liking, and enter a test mode to check which buttons work or are shorted, without hassling with the programming software.
-Attempted to plug in my LED harness. IT HAS ALL 10 PINS!
-"Default" mame button assignments are NOT what the ultimarc board says they should be.
A picture or drawing of the harness might help. If I remember right, the pin header on the IPAC board didn't have any key blocks in it, just spaces, so any plug with the right spacing should fit on it. I first played with it using a plug I yanked out of an old CD player that had gone bad. That fit on the pins just fine.