Lamps fed through one insulation-displacement (IDC) connector on a light board work for about ten minutes, then stop until the plug is wiggled or reseated.

Lamp board plug works for a few minutes then cuts out: cracked header solder

Cause: A cracked solder joint where the header pin is soldered to the board, not the IDC plug itself.

Checks

• Remove the light board and inspect the header pins' solder joints on the back; look for a ring crack around the pin.
• Check that the wires are fully seated in the IDC plug.

Fix

• Reflow the header pins with fresh solder.
• If the IDC plug is also worn, re-punch the wires with an IDC tool or replace it with a crimped .156 connector.

Systems

• WPC Fliptronics

Games

• Doctor Who

Related tips

• Resets from worn power connectors between transformer, driver and CPU boards
• Lamp matrix connectors on the driver board
• Use crimped Trifurcon pins, not IDC, when replacing connectors

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