This is a Phoenix arcade game pcb.

It booted up, but colors were wrong, and player 1 fire did not work.

I unplugged the cables between the two boards, and plugged them in again.

Colors now ok, but the fire button still not works.

I traced the fire button trace to a 74LS157 that did not produce any output for the pin used.

I pulled the chip, mounted a socket with a new chip, and now the game works like it should.