Twilight Zone: diode mod to cool the clock with stock bulbs
Steps
- Replace the zero ohm links at D1 to D4 on the clock board with 1N4004 diodes, keeping the #86 bulbs.
- Fit D2 and D3 with their bands opposite the board markings, so lamps 1 and 4 share one AC half-cycle while lamps 2 and 3 take the other.
- Drill two 1/4 inch vent holes in the top of the clock housing above the top two lamps.
- This drops clock power from about 8 W to about 6 W while keeping the stock look.
Systems
Games
Related tips
- Twilight Zone: "clock is broken" error
- Addams Family: both right flippers stick up until the left button is pressed
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- Clamp diode mod to protect U5
- Testing a coil diode
- Testing the diode on a coil
- Which way a coil diode goes
- Which way a coil diode goes
Source: Repairing Williams/Bally WPC Pinball Games from 1990 to 1999, Part Three, Clay Harrell (pinrepair.com)