I was adjusting the right pop bumper stack under the play field with the power on. I touched the EOS switches and heard a hum and blew a fuse on the power aux board. I replaced fuse and this is what happens: This happens ONLY when I start a game NOT when just powered up. when I press the credit button the right pop bumper locks up.... I thought it might be a 1N4003 #19 diode on the power aux board but that did not cure it. If I unhook the ground thin wire on the right pop bumper everything works as it should. HELP!

nope every thing works great. I ground transistor 73 and it pulls the pop bumper. I was not to think that it could be a pre driver?

the credit (start) button. I will do the switch edge and see.

bad zen 1/2 watt diode on cpu board. Fixed