Stellar Wars (Williams, 1979): Troubleshooting and System 6 Replacement Boards
Is your Stellar Wars by Williams has no display with the master LED blinking, a slow startup, an inconsistent boot, or a stuck pop 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.
Stellar Wars (Williams, 1979): Overview
Released in 1979, Stellar Wars is a well-regarded sci-fi System 6 title.
- Manufacturer: Williams
- Year: 1979
- Electronic system: Williams System 6
- Type: solid state
- Theme: space battle / science fiction

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).

Stellar Wars-Specific Issues (Forum Reports)
- No display at all, master LED blinking: often a collapsed 5V (measured at 2.7V instead of 5V).
- Slow startup: resolved by replacing the 4 large power-supply capacitors.
- Inconsistent boot: both CPU LEDs light then go out, with the self-test varying from one power-up to the next.
- Stuck pop bumper: the top-right bumper coil stays energized; the switches under the bumper then no longer make contact.
- Faulty sound: missing, doubled, or distorted sounds.
Compatible Replacement Boards for Stellar Wars
- 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 — Stellar Wars Williams
I have no display and the master LED blinks.
Often a collapsed 5V (measured ~2.7V). Rework the power supply; replacing the 4 large capacitors also cures slow startup. The WillFA7 replaces MPU and driver.
My pop bumper is stuck on.
The top-right bumper coil stays energized and the switches stop making contact. 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 Stellar Wars; 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)
- Tri Zone (Williams, 1979)
- Laser Ball (Williams, 1979)
- Scorpion (Williams, 1980)