Pokerino (Williams, 1978): Troubleshooting and System 4 Replacement Boards
Is your Pokerino by Williams has a shorted rectifier bridge, a worn 40-pin ribbon, dead driver transistors, or burnt coils? These symptoms are typical of Williams System 4 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.
Pokerino (Williams, 1978): Overview
Released in 1978, Pokerino is a well-liked title of Williams' first solid-state generation.
- Manufacturer: Williams
- Year: 1978
- Electronic system: Williams System 4
- Type: solid state
- Theme: poker / cards
Common Issues (System 4)
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).
Pokerino-Specific Issues (Forum Reports)
- Shorted rectifier bridge: a Williams design flaw (no fuse between the transformer and the bridge); the large lamp and coil power-supply bridges often blow.
- 40-pin interconnect ribbon: the link between the CPU board and the Driver board often needs replacing.
- Dead transistors: faulty driver transistors on the Driver board.
- Burnt coils under the playfield: a consequence of a stuck driver or an unsuitable fuse.
- NiCad battery on the MPU: corrosion that absolutely must be neutralized.
Compatible Replacement Boards for Pokerino
- WillFA7 — 2-in-1 board (MPU + Driver) compatible with System 3 to 7 (System 4 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 — Pokerino Williams
My rectifier bridge keeps shorting.
A known Williams design flaw (no fuse between transformer and bridge). Replace the bridge; the WillFA7 replaces the driver stage and eliminates the 40-pin ribbon.
I have burnt coils under the playfield.
Usually a stuck driver or an unsuitable fuse. The WillFA7 renews the driver transistors; use the correct fuses.
Do I need to keep the original battery?
No. The WillFA7 runs without a battery and eliminates the #1 cause of corrosion on System 4 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 Pokerino; 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
- Phoenix (Williams, 1978)
- Disco Fever (Williams, 1978)
- Contact (Williams, 1978)
- Lucky Seven (Williams, 1978)
