The spinning wheel in the backbox and the Ferris wheel motor don't run, and the drop target and Hurricane optos don't register. The motors run if powered directly, and 12 V is present at the board test point, but there is no voltage at the devices.

Backbox wheel and Ferris wheel motors dead with no 12 V: J116 left unplugged

Cause: The 12 V feed for these devices (grey with yellow stripe wires) leaves the power driver board through J116, which had been left unplugged.

Checks

• Measure 12 V at the devices themselves, not just at the board test point.
• Check the small three-wire connectors at the lower left of the power driver board; make sure J116 is fitted and its pins are sound.

Fix

• Plug J116 back in (repin it if the pins are worn) and recheck voltage at the motors and opto boards.

Systems

• WPC Dot Matrix

Games

• Hurricane

Related tips

• GI string dead with a scorched connector
• GI out because the GI connector burned
• Resets from worn power connectors between transformer, driver and CPU boards
• Several solenoids and a lamp group dead: reseat the CPU-to-driver ribbon
• Why the early white J115 plug overheats
• Repair a burnt GI connector on the driver board
• J115 wire colors on games before Twilight Zone
• GI connectors on the driver board

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