At power-up every controlled lamp comes on and stays on and the backbox motor runs; the flipper power fuse (F5 on the playfield power board) then blows. After a new fuse the game still won't boot properly and the CPU's PIA LED stays on solid.

All lamps come on, flipper fuse blows and the game won't boot: failed replacement NVRAM

Cause: The cheap replacement NVRAM fitted some 40 games earlier had failed, so the CPU did not start up properly and left outputs on.

Checks

• Check the CPU board's status LEDs during boot.
• Swap in a known good NVRAM (and reseat the PIAs) before replacing chips.

Fix

• Replace the failed NVRAM with a good one, then set up the game again (scores and settings are lost).

Systems

• Data East CPU Version 3

Games

• Star Trek

Related tips

• New CPU board locks up when the coin door buttons are plugged in: reseat the PIA
• Replacement CPU board won't boot with the old processor: socket contact
• CPU still will not boot after the basics
• Program runs but the PIAs never respond
• CPU board PIA positions and jobs
• Test program does not run at all
• PIAs or the EPROM are never selected
• Flippers and special coils all dead

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