After rebuilding the power supply, everything works except the displays; the display high voltages are missing and the small display fuse had blown.

No displays after power supply work: dirty display fuse holder and edge connectors

Cause: The display fuse holder and the two display edge connectors were dirty and not making good contact. (During the rebuild, a lock washer fitted under the -12 V regulator had also shorted it to the frame, killing the regulator and two diodes.)

Checks

• Measure the voltage across the display fuse holder, not just the fuse.
• Check the AC feed from the small display transformer with the supply unplugged.
• Make sure each regulator is insulated from the frame as originally fitted.

Fix

• Clean the display fuse holder and the display edge connectors; replace any parts damaged by a shorted regulator.

System 1 display supplies run at high voltage; work with the game unplugged.

Systems

• Gottlieb System 1

Games

• Cleopatra

Related tips

• +60 V or +42 V display voltage missing
• Power supply bring-up, step 3: displays
• Never plug displays with the power on

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