The power driver board shows heavy burning at the header that sends transformer AC up to the Fliptronic board; the fuse for that circuit did not blow.

Burned power driver board traces at the header feeding AC to the Fliptronic board

Cause: Two pins in the header arced across, and the arc burned through the traces both on the surface and inside the board layers.

Checks

• Inspect the header pins and the board around them, front and back, for scorching and lifted or burnt traces.
• Confirm the fuse for that circuit is the value printed on the board or in the manual; an incorrect fuse can let damage like this happen without blowing.

Fix

• Remove the burnt header and damaged section, then replace every damaged trace with heavy (about 14 gauge) solid wire run on the back of the board to the remaining header and to the bridge rectifier.
• Remember the same header also carries AC used elsewhere on the power driver board, so every path through it has to be restored.
• Fit a new header and the correct fuse.

These are transformer secondary AC circuits that feed the flipper supply; unplug the game before working on the board.

Systems

• WPC Fliptronics

Games

• Twilight Zone

Related tips

• Gumball diverter, popper and two bumpers dead in test: faulty CPU ribbon
• Resets from worn power connectors between transformer, driver and CPU boards
• GI string dead with a scorched connector
• GI out because the GI connector burned
• No coils, lamps, GI or flashers but display and sound work: check blanking
• GI connectors on the driver board
• Repair a burnt GI connector on the driver board
• Check the AC power input connectors too

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