The backbox cannon (ball popper) does nothing when tested on its own, but fires whenever the diverter fires, in test and in play.

Backglass cannon fires with the diverter instead of on its own: plug swapped

Cause: The cannon's plug on the power driver board is on the wrong connector.

Checks

• In solenoid test, select the cannon and press Start: the display shows the wire colours and the driver board connector it should use.
• Compare that with where the plugs are fitted.

Fix

• Move the plug to the connector the test screen and manual call for, then retest all coils.

Systems

• WPC-95

Games

• Cirqus Voltaire

Related tips

• GI out because the GI connector burned
• Repair a burnt GI connector on the driver board
• J115 wire colors from Twilight Zone on (Corvette example)
• GI connectors on the driver board
• Two wires on one GI pin
• Check the AC power input connectors too
• Resets from worn power connectors between transformer, driver and CPU boards
• Lamp matrix connectors on the driver board

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