The game resets during play.

Game keeps resetting: replace the 5101 RAM (an NVRAM works)

Cause: The 5101 RAM on the CPU board had failed.

Checks

• Check the 5 V supply and the CPU board connectors first.
• Look at the 5101 RAM and its socket for corrosion.

Fix

• Replace the 5101 with an NVRAM replacement (or a new 5101).

Systems

• Williams System 6 / 6A

Games

• Firepower

Related tips

• Game powers up in audit mode instead of attract mode
• Boots into audit mode every power-up with good batteries: bad 5101 RAM
• System 6 won't boot and fails the 5101 RAM test even after replacing it: bad 5101 stock
• Leon's test EPROM fitted but the LEDs do not start flashing
• 5101 RAM at U8 fails often; speed matters
• Two flashes only: U8 5101 RAM
• Odd high scores usually mean a bad 5101 RAM
• Locks up when a second game is started: bad 5101 RAM

Source: Pinball Repair help group!! (Facebook group)