A flasher is lit all the time or brighter than the rest.

A flasher stays on or is very bright

Cause: A shorted TIP102 or pre-driver, or sometimes the 74LS374 latch.

Checks

• Test the driver and pre-driver transistors.

Fix

• Replace the bad transistor or latch.

Systems

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

Related tips

• Flasher glows full bright until the bulb blows: shorted driver transistor
• One flasher fires all the saucer flashers: backbox flasher feed on the wrong header
• Flasher over the upper right flipper melts its plastic: the flasher is stuck on
• Launch coil locks on and blows its transistor and fuse every time it is tested
• Auto-plunger coil energized as soon as the coin door closes: coil shorted to its bracket
• Top popper and both 3-bank coils dead after a rebuild: pinched 50 V wire, blown F104
• Brand-new coil burns up soon after fitting: find the reason the old one burned
• Left mini-playfield magnet dead, about 8 V at it: F101 blows, shorted Q26

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