1993 Williams Twilight Zone Repair

Fixed a Twilight zone today. I never forget to do this, but I actually forgot to take a photo of this game. No matter, as this repair was almost the same as the Bride of Pinbot I fixed earlier this year.

Repair Problems & Fixes:

Problem: Game Resets during gameplay.
Fix: Replaced bridge rectifier and capacitor for 5v circuit on Driver board. Also replaced A/C input connectors and 5v output connectors (also eliminated Z daisy chain connector). Replaced 5V input connector on MPU. Reflowed solder on all .156 header pins on Driver board.

Problem: Game loses memory upon A/C power loss.
Fix: Replaced MPU memory chip with FM1608 NV RAM. No batteries required in the future.

Problem: Ball won’t kick out to ball trough when game starts.
Fix: Replaced blown fuse on Driver board.

Other work done:

– Replaced 10 bulbs and 1 flasher
– Replaced white rubber rings on game.
– Cleaned and waxed playfield.
– Adjusted Buy-in Switch below shooter on front of cab (wasn’t working).

Parts Replaced:

1 – 15000uf, 25V Capacitor
1 – 35A, 400V Bridge Rectifier
1 – 5A Slow Blow Fuse
10 – #44 6.3v Blubs
1 – #89 Flasher Bulb
1 – FM1608 Ramtron NVRAM
2 – 7 Pin Molex Connector Housing
1 – 9 Pin Molex Connector Housing
13 – Molex Connector Pins
1 – White Rubber Set

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