When it is in audit mode, open the coin door and power cycle twice. If it goes back into attract mode something corrupted the RAM. If it refuses to go into attract mode, the CPU cannot access the RAM properly.

WMS System 6 game like Laser Ball the NVRAM can be cleared/reset with the command memory switches on the MPU board. There is usually a stapled card in the backbox that tells you how to do it.

command memory switch number seven set to on, rest off
coin door open and game on
push the cpu board diag button, CPU board leds should blink twice
push the command memory entry switch, LED should blink once.
Power cycle the game two times and you should be back at attract mode with factory default settings.

If the game is crashing and booting into audit mode the RAM is getting corrupted for some reason. If the 40pin interconnect, an EPROM/RAM IC socket, or even a power supply issue could be causing the software to crash and the RAM to corrupt. When the game detects corrupted RAM you boot into audit mode. That is probably what is going on.

Good picture of the MPU? Does it have scanbe IC sockets? Was the CPU/Driver board interconnect reworked? Crummy IC sockets, power supply, connector solder joint broken, and 40p interconnect major causes of problems in those games.