Tri Zone (Williams, 1979): faults and System 6 replacement boards
Does your Williams Tri Zone have a leaking battery, missing display segments, dead bumpers or start on its own? These symptoms are typical of Williams System 6 pinball machines, whose original boards (MPU, Driver, power supply) are now over 40 years old. Good news: the WillFA7 replacement board, Plug & Play and battery-free, gives your machine a second life.
Tri Zone (Williams, 1979): overview
Released in 1979, Tri Zone is a Williams System 6 pinball machine themed around danger and risk zones. A fast, edgy title from this solid state generation.
- Manufacturer: Williams
- Year: 1979
- Electronic system: Williams System 6
- Type: electronic pinball (solid state)
- Theme: danger / risk zones
Common faults (System 6)
On Williams System 3 to 7, recurring faults come from ageing: leaking NiCad battery on the MPU (corrosion, the no.1 cause of dead boards), worn 40-pin connector MPU↔Driver (the best-known weak point), resets/reboots on 5 V drop (headers and power connectors to re-solder), tired power supply capacitors, displays with missing segments (connectors, display resistors), and a blown solenoid fuse (stuck slingshot or bumper).
Issues specific to Tri Zone (forum feedback)
- Battery corrosion: green corrosion visible even inside the interconnect connectors — to be neutralised urgently.
- Missing display segments: e.g. the bottom segment off on all displays, and burnt 10K resistors on the master display board (seven top left, seven top right).
- The game starts on its own: with one credit, the game starts a game as soon as power is applied instead of staying in attract.
- Faulty jet bumper: often a dead PIA or 7408 on the Driver board.
- 40-pin connector: to be replaced to make the machine reliable.
Replacement boards compatible with Tri Zone
- WillFA7 — 2-in-1 board (MPU + Driver) compatible with System 3 to 7, System 7 included.
The WillFA7 replaces the original MPU and Driver board (start-up, logic resets, coil driving, battery-free memory) and does away with the fragile 40-pin ribbon. Pure power supply faults (capacitors, 5 V, power connectors) still need handling on the power supply side; our support guides you.
Plug & Play installation, battery-free, free tutorials and support. Contact us.
FAQ — Tri Zone Williams
The battery leaked into the connectors.
Clean the corrosion and check the traces. The WillFA7 works without a battery and permanently removes this risk.
A segment is missing on all displays.
Check the burnt 10K resistors on the master display board. That is on the display side; the WillFA7 makes the driving reliable.
My jet bumper no longer works.
Often a dead PIA or 7408 on the Driver board. The WillFA7 replaces the Driver stage.
Should I keep the original battery?
No. The WillFA7 works without a battery and removes the no.1 cause of corrosion on System 6.
How long does it take to install a replacement board?
Installation is Plug & Play: a few minutes, no soldering, with tutorials and free support.
Does a battery-free board keep the settings and high scores?
Yes. Modern replacement boards use non-volatile memory: no more battery, no more corrosion, and the settings are kept when powered off.
Step-by-step diagnosis
- Power off, visual inspection: look for any trace of battery or corrosion on the MPU of your Tri Zone; remove the NiCad battery if it is still present.
- Power supply: check the 5 V and the fuses; resolder the power supply and MPU headers if the voltage drops or the game resets.
- Connectors: re-pin the oxidised Molex connectors, especially the MPU↔Driver link.
- Coils: check the solenoid fuses and the 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: check start-up, credits, coils and displays; remember that the WillFA7 replaces MPU + Driver. If needed, contact free support.
See also
- Flash (Williams, 1979)
- Stellar Wars (Williams, 1979)
- Time Warp (Williams, 1979)
- Gorgar (Williams, 1979)
