Varkon (Williams, 1982): Troubleshooting and System 7 Replacement Boards
Is your Varkon by Williams has flippers that don't respond to the joysticks, a ball stuck on the lower playfield, won't start, or weak displays? These symptoms are typical of Williams System 7 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.
Varkon (Williams, 1982): Overview
Released in 1982, Varkon is a solid-state pinball housed in a video-game cabinet, with the playfield shown vertically via a mirror and flippers controlled by joysticks — very rare (about 90 units).
- Manufacturer: Williams
- Year: 1982
- Electronic system: Williams System 7
- Type: solid state, upright cabinet
- Theme: novelty / arcade
Common Issues (System 7)
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).
Varkon-Specific Issues (Forum Reports)
- Flippers no longer respond to the vertical joysticks: check the joystick micro-switches and control mechanism before suspecting the electronics.
- Ball stuck on the lower playfield: accessible through the window of the upper playfield; clean the switches and guides.
- Won't start or resets: corroded battery and worn 40-pin connector, typical of System 7.
- No sound: the Type 2 sound board to diagnose.
- Weak displays and lamps behind the mirror: the mirror is a semi-reflective plastic; clean it and check the display power supply.
- Rare specific parts: only about 90 units and a video-type cabinet; preserve and repair the original parts.
Compatible Replacement Boards for Varkon
- 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 (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 — Varkon Williams
My flippers don't respond to the joysticks.
Check the joystick micro-switches and control mechanism first, before the electronics. On the board side, the WillFA7 replaces MPU and driver.
A ball is stuck on the lower playfield.
Access it through the upper-playfield window and clean the switches and guides.
Do I need to keep the original battery?
No. The WillFA7 runs without a battery and eliminates the #1 cause of corrosion on System 7 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 Varkon; 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
- Warlok (Williams, 1982)
- Cosmic Gunfight (Williams, 1982)
- Barracora (Williams, 1981)
- Solar Fire (Williams, 1981)
