Flash (Williams, 1979): faults and System 6 replacement boards

June 25, 2026

Is your Williams Flash not booting, resetting, blowing the solenoid fuse or showing missing segments? 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.

Flash (Williams, 1979): overview

Released in 1979, Flash is a major Williams hit on System 6, with a lightning and superhero theme. One of the most-produced pinball machines of its era, famous for its sound effects and its central lightning bolt.

Manufacturer: Williams
Year: 1979
Electronic system: Williams System 6
Type: solid-state pinball machine
Theme: lightning / superhero

WillFA7 board for Williams System 6 — Flash — The WillFA7 board replaces the MPU and Driver board (System 3 to 7).

Common faults (System 6)

On Williams System 3 to 7, recurring faults stem from ageing: a leaking NiCad battery on the MPU (corrosion, the No. 1 cause of dead boards), connectors that overheat or burn (power supply) and cracked connector solder joints, resets/reboots on a 5 V drop (power supply and MPU headers to resolder), a rectifier bridge that fails short-circuit (Williams fitted no fuse between transformer and bridge), displays with missing segments or digits (connectors to clean), and a 28 V solenoid fuse that blows (stuck slingshot).

Checking a Williams System 6 board with a multimeter — Flash — A multimeter is essential to check voltages, fuses and continuity.

Flash specific issues (forum feedback)

MPU that won't boot: nothing on the displays, LED flashes then goes out; suspect the ROM sockets and the interconnect headers.
Reset on voltage drop: these Williams are known for their poor sockets and interconnects; reflow the power supply header solder joints and replace the 5 V headers (power supply and MPU).
Solenoid fuse F2 (28 V, 2.5 A) blowing: often a left slingshot left actuated.
Weak or "machine-gunning" right kicker: switch contact and adjustment to check.
Displays with no digits: while all the lamps work.

Replacement boards compatible with Flash

WillFA7 — 2-in-1 board (MPU + Driver) compatible with System 3 to 7, System 7 included.

WillFA7 replacement board — Flash — The WillFA7: battery-free replacement, Plug & Play installation.

The WillFA7 replaces the original MPU and Driver board (start-up, logic resets, coil control, battery-free memory) and eliminates the fragile sockets/interconnects. Purely power-supply faults (rectifier bridge, power connectors) still need addressing on the power supply side; our support guides you.

Plug & Play installation, battery-free, tutorials and free support. Contact us.

FAQ — Flash Williams

My Flash won't boot.
Suspect the ROM sockets and the interconnect headers. The WillFA7 replaces MPU and Driver and removes these weak points, battery-free.

My game resets on a voltage drop.
Reflow the 5 V headers (power supply and MPU). The WillFA7 makes the logic side reliable; the power supply still needs checking.

The solenoid fuse blows.
Often a stuck left slingshot. The WillFA7 replaces the Driver stage; check the switch concerned.

Should I keep the original battery?
No. The WillFA7 runs battery-free and removes the No. 1 cause of corrosion on System 6 machines.

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 battery or corrosion trace on the MPU of your Flash; 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 plug or unplug a display while powered; 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.