Firing a coil by grounding it with a clip lead

Steps

• Game on in attract mode, playfield up, coin door closed on 1993 and later games.
• Clip one end of a jumper to the metal side rail.
• Briefly touch the other end to the coil's ground lug: the lug with the single wire (often brown). On a flipper coil use the center lug; the supply wire is the thicker violet or red one.
• The coil should fire. If not, the coil is bad or its fuse is blown.
• Touching the power lug by mistake shorts the coil supply to ground and resets the game or blows a fuse.

Coil circuits carry about 50 V DC; touching the clip to the wrong lug shorts the supply and can blow a fuse.

Systems

• WPC Alpha-Numeric
• WPC Dot Matrix
• WPC Fliptronics
• WPC DCS
• WPC-Security (WPC-S)
• WPC-95

Related tips

• Grounding test for WPC coils 1-8
• Firing each coil from the WPC solenoid test
• Two or more coils fire together
• Checking for power at a coil with the game on
• Coil-not-working checklist
• Auto ball launcher stopped working: check the wires at the coil
• Spotting the +50 V wire on a coil
• No 50 V coils work

Source: Repairing Williams/Bally WPC Pinball Games from 1990 to 1999, Part Two, Clay Harrell (pinrepair.com)