Killer Instinct 2 Volume control

Hi all,

I acquired a KI2 board for repair. It boots with no sound and the diag points to the U10. No mystery there.

While the game is running (no sound still) if I hit P1 Button 3 the volume control screen comes up. If I go into the button test menu P1 button 3 lights up normally and no other buttons light up on screen when P1 B3 is pressed, as normal.

Any KI experts that might know why the volume control screen comes up with P1B3 is pressed?

The cab had dedicated volume control buttons. The pcb receives volume control through header J3 pins 2 and 3 (2=down,3=up). I’d start there. Got anything connected to j3? P1B3 and that might be shorted, check with a multimeter.

Keep pressing P1B3 during attract mode to see if it goes up or down. Narrow it down to one of the above pins perhaps.

Also the killer instinct pcb has a volume setting in the main menu. If that is turned down you get no sound.

Nothing hits continuity between P1B3 and J3 2 and 3 unfortunately. The hunt continues.

I am thinking my no sound is a eprom issue. Waiting for some chips to come in the mail. I get 2 tones in the sound test indicating U10 eprom.

KI sound EPROM's go bad often. Start there.

Verified the ROMs. They all check out against MAME. Possible the U10 RAM went bad?