John's Arcade Forum - Classic Arcade and Pinball Collecting and Restoring Discussion Forum - RETRO MAME - Nintendo Vs Forum

I built a cocktail style arcade with 2 sets of controls for Player 1 and Player 2 including buttons to select 1 Player or 2 Players.   I installed a 412 in 1 Jamma board and wired it up according to the wiring diagram from the retailer.  Upon completion I went into the System menu and made a couple of changes such as setting it to Free Play and Free Browse. The player 1 side works fine with no apparent problems but nothing on the Player 2 side works at all.  Using the joystick or buttons does absolutely nothing. When I go into the System setup menu everything seems to relate to “Player 1” but I don’t see anything related to “Player 2”.

Any suggestions as to where I should be looking to find the problem with the Player 2 controls?

Thanks.

Are you saying player 2 doesn't work to select a game in the menu, or player 2 controls don't  work when playing a 2 player game?

On those PCBs pin 27 both sides of the JAMMA connector is button 6. The board is configured to have 2 8-way joysticks and 6 buttons.
Most JAMMA cabs/wiring have that pin as ground.
You need to pull out that wire from the JAMMA connector in your cab.
I don't know if that will fix your issue but for sure pin 27 both sides should not be wired to ground.

Also try any other JAMMA PCB. If another PCB works your board may be faulty.
If it doesn't work check under your control panel and make sure your grounds are connected and common.

Thanks guys.  Its working now. Somehow, one of the ground wires slipped off of the joystick and that disconnected everything on the player 2 side from ground.  It was just barely off of the lug so it was not easy to spot.  Thanks again.