A coil locks on as soon as the game powers up.

A coil stays energized

Cause: Its TIP36 and/or TIP102 driver has shorted; the pre-driver may also be bad.

Checks

• With the game off, test the transistors (grounding the tab does not help with this fault).

Fix

• Power off at once, replace the shorted driver and its pre-driver, and check the coil before powering up again.

Systems

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

Related tips

• Coil pulls in as soon as the game is switched on
• Auto-plunger coil energized as soon as the coin door closes: coil shorted to its bracket
• Coil-not-working checklist
• Driver transistor dies after fitting a coil that has a diode
• Grounding test for WPC coils 1-8
• No 50 V coils work
• Checking the coil supply at TP6
• Firing each coil from the WPC solenoid test

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