With an aftermarket CPU board fitted, the game boots, all coils and switches (including start) work in test and there are credits, but pressing start does nothing.
Replacement CPU board: game won't start though tests pass: DIP switches reversed
Cause: The replacement board's DIP switches had been set in the opposite direction.
Checks
- Compare the DIP settings with the replacement board's own instructions, watching which way is ON.
- Make sure the board is set for the right game.
Fix
- Set the DIP switches the right way round.
Systems
Games
Related tips
- CPU DIP switches: used by System 3, ignored from System 4 on
- Blanking circuit parts: C32/C84, IC7, Q5/Q1 and IC23
- Is it the CPU board or the driver board? Boot the CPU alone
- System 6 won't boot and fails the 5101 RAM test even after replacing it: bad 5101 stock
- Blanking stays low: timer, C31 and Q5
- Zero audits, restore factory settings or auto-cycle with the DIP switches
- Check the blanking and IRQ signals on a booting CPU
- Leon's test EPROM fitted but the LEDs do not start flashing
Source: Pinball Repair help group!! (Facebook group)