Tri Zone (Williams, 1979): Troubleshooting and System 6 Replacement Boards
Is your Tri Zone by Williams has battery corrosion, missing display segments, a game that starts by itself, or a faulty jet bumper? These symptoms are typical of Williams System 6 pinball machines whose original boards (MPU, driver, power supply) are now over 40 years old. The good news: the WillFA7 replacement board, Plug & Play and battery-free, brings your machine back to life.
Tri Zone (Williams, 1979): Overview
Released in 1979, Tri Zone is a fast, nervous System 6 title.
- Manufacturer: Williams
- Year: 1979
- Electronic system: Williams System 6
- Type: solid state
- Theme: danger / risk zones
Common Issues (System 6)
On Williams System 3 to 7 pinball machines, recurring failures stem from aging: leaking NiCad battery on the MPU (corrosion — the #1 cause of dead boards), worn 40-pin MPU-to-driver connector (the single most common failure point), resets/reboots from 5V drops (power headers and connectors need re-soldering), tired power supply capacitors, displays with missing segments, and solenoid fuse blowing (stuck slingshot or pop bumper).
Tri Zone-Specific Issues (Forum Reports)
- Battery corrosion: green corrosion visible right into the interconnect connectors — neutralize it urgently.
- Missing display segments: e.g. the bottom segment dark on all displays, with burnt 10K resistors on the master display board (seven at top-left, seven at top-right).
- Game starts by itself: with a credit present, it launches a game at power-on instead of staying in attract mode.
- Faulty jet bumper: often a dead PIA or 7408 on the Driver board.
- 40-pin connector: replace it to make the machine reliable.
Compatible Replacement Boards for Tri Zone
- WillFA7 — 2-in-1 board (MPU + Driver) compatible with System 3 to 7 (System 6 included).
The WillFA7 replaces the original MPU and driver board (startup, logic resets, solenoid control, battery-free memory) and eliminates the fragile 40-pin ribbon cable. Purely power-supply issues (5V/12V, capacitors, power connectors) and the sound board are addressed separately; our support team can guide you.
Installation is Plug & Play, battery-free, with tutorials and free support. Contact us.
FAQ — Tri Zone Williams
My Tri Zone starts a game by itself at power-on.
With a credit present it launches instead of staying in attract mode — check the switch matrix and start circuit. The WillFA7 provides reliable, battery-free logic.
My jet bumper doesn't work.
Often a dead PIA or 7408 on the Driver board. The WillFA7 replaces the driver stage.
Do I need to keep the original battery?
No. The WillFA7 runs without a battery and eliminates the #1 cause of corrosion on System 6 machines.
How long does installation take?
Installation is Plug & Play: just a few minutes, no soldering required, with tutorials and free support.
Does a battery-free board retain settings and high scores?
Yes. Modern replacement boards use NVRAM: no battery, no corrosion, and settings are preserved when powered off.
Step-by-Step Diagnostics
- With power off, visual inspection: look for any signs of battery leakage or corrosion on the MPU of your Tri Zone; remove the NiCad battery if still present.
- Power supply: check the 5V rail and fuses; re-solder power supply headers and MPU headers if voltage drops or the game resets.
- Connectors: re-pin oxidized Molex connectors, especially the MPU-to-driver connection.
- Solenoids: check solenoid fuses and switches (stuck slingshot) before powering back on.
- Displays: never connect or disconnect a display while powered on; test with a known good display.
- Final test: verify startup, credits, solenoids, and displays; remember the WillFA7 replaces MPU + driver. If needed, contact free support.
Useful Guides
- How much does pinball machine repair cost? A price guide
- How much is my pinball machine worth? Value and estimation
- Pinball machine leg sizes: the complete guide
- Which board for a Williams System 3 to 7?
See Also
- Time Warp (Williams, 1979)
- Stellar Wars (Williams, 1979)
- Laser Ball (Williams, 1979)
- Scorpion (Williams, 1980)
