Black Knight (Williams, 1980): Troubleshooting and System 7 Replacement Boards
Is your Black Knight by Williams not starting, resetting, encountering stuck solenoids, or missing display segments? 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.
Black Knight (Williams, 1980): Overview
Released in 1980, Black Knight is an iconic Williams System 7 pinball machine with a multi-level playfield, the Magna-Save feature, multiball, and speech synthesis — one of the most celebrated pinball machines of all time.
- Manufacturer: Williams
- Year: 1980
- Electronic system: Williams System 7
- Type: solid state, multiball, Magna-Save, multi-level playfield, speech
- Theme: medieval knights
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).
Black Knight-Specific Issues (Forum Reports)
- Multi-level playfield connector: the head-to-body connector must be firmly seated for the upper playfield to function.
- Magna-Save not working: check the magnet relay and head-to-body connector.
- Multiball lock issues: trough and ball lock switches need adjusting.
- 40-pin connector: if the female housing is yellowed/grimy rather than white, replace both male and female — this is THE weak point of System 3-7 machines.
- NiCad battery on MPU: corrosion must be neutralized immediately.
- Missing display digits: check resistors R1-R7 on the display board; replace with 1/2-watt resistors.
Compatible Replacement Boards for Black Knight
- WillFA7 — 2-in-1 board (MPU + Driver) compatible with System 3 to 7, including System 7.
The WillFA7 replaces the original MPU and driver board (startup, logic resets, solenoid control, multiball, battery-free memory) and eliminates the fragile 40-pin ribbon cable. Mechanical adjustments for multiball, the Magna-Save relay, and the sound board need to be addressed separately; our support team can guide you.
Installation is Plug & Play, battery-free, with tutorials and free support. Contact us.
FAQ — Black Knight Williams
My Black Knight won't start or keeps resetting.
Check the 5V and 12V at the MPU. The WillFA7 replaces MPU and driver and stabilizes startup; the power supply still needs checking.
The Magna-Save doesn't work.
Check the magnet relay and head-to-body connector. The WillFA7 handles the logic side; the relay is addressed separately.
Does the WillFA7 support System 7 and multiball?
Yes. It covers System 3 to 7 (System 7 included) and controls the logic, multiball, and solenoids.
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 Black Knight; 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
- Jungle Lord (Williams, 1981)
- Pharaoh (Williams, 1981)
- Solar Fire (Williams, 1981)
- Barracora (Williams, 1981)
