Joker Poker (Gottlieb, 1978): faults and System 1 replacement boards
Is your Joker Poker (Gottlieb, 1978) buzzing loudly at power-on, are the displays fading until they go out or are they showing zeros? This Gottlieb pinball with a cards/poker theme runs on System 1, known to be temperamental. Here are the typical faults reported on the forums and the battery-free replacement solutions.
Joker Poker overview
Released in 1978, the Joker Poker is a Gottlieb solid-state pinball built on System 1. Its casino theme features playing cards, poker hands and the famous Joker, in a hunt for winning combinations.
- Manufacturer: Gottlieb
- Year: 1978
- System: Gottlieb System 1
- Type: solid state (alphanumeric displays)
- Theme: playing cards, poker, casino
Common faults (System 1)
The Gottlieb System 1 shares a set of well-known weaknesses, regardless of the game:
- Leaking battery: the NiCad battery soldered onto the MPU board leaks over time and corrodes traces and components. It's the number-one fault — remove it without delay.
- Poor grounding: the original ground wiring is undersized and causes resets and erratic behaviour (the "ground mods" are practically mandatory).
- Corroded connectors: the Molex connectors, especially the MPU↔Driver link (46 pins), lose contact and need re-pinning.
- Power supply: unstable 5 V, tired bridge rectifiers and an overheating transformer lead to crashes.
- Displays: digits that fade, flicker or stay frozen at zero.
Joker Poker-specific problems (forums)
- Buzzing at power-on + dead displays: often a power-supply problem; check the bridge rectifiers and the transformer's heat first.
- Fading displays: brightness that drops until it goes out, a classic of the System 1 power supply and displays.
- Showing zeros: the game stays frozen on zeros even when you add a credit — look on the CPU and connector side.
- Stubborn credits / free play: erratic credit counting, to be corrected on the settings and electronics side.
- Grounds and CPU connectors: the Joker Poker is known for weak grounds; do the ground mods and re-pin the connectors going to the CPU.
- After transport: with the power off, check the proper crimping and seating of the cables between the head and the cabinet.
Joker Poker-compatible replacement boards
The Joker Poker is built on the Gottlieb System 1, a platform known to be fragile (leaking battery, weak grounds, oxidised connectors). Pinballs Store offers battery-free replacement solutions to make it reliable again:
- Gosof — replacement sound board.
For a CPU/Driver board dedicated to System 1, contact us: we'll point you to the best solution for your Joker Poker. Plug & Play installation, battery-free, free support.
FAQ — Joker Poker Gottlieb
What year was the Joker Poker released?
In 1978. It's a Gottlieb solid-state pinball on the System 1 platform.
Why does my Joker Poker buzz with dead displays?
It's typically a power-supply problem: tired bridge rectifiers and an overheating transformer. Check and replace the bridge rectifiers first.
Should I remove the battery from the MPU board?
Yes, immediately. The original NiCad battery eventually leaks and destroys the board. A battery-free replacement board permanently eliminates this risk.
Is there a replacement board for the Joker Poker?
Yes. Contact us for the right System 1 CPU/Driver solution; installation is Plug & Play, battery-free, with free support.
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 marks on the MPU of your Joker Poker; remove the NiCad battery if it is still present.
- Power supply: measure the 5 V and check that it reaches the MPU (re-solder the regulator or Q1 if the voltage drops).
- Grounds: apply the “ground mods” between the boards (CPU, Driver, power supply, sound).
- Connectors: re-pin the oxidised Molex connectors, especially the MPU↔Driver link.
- Displays: never plug or unplug a display while powered on; test with a known-good display.
- Final test: check start-up, credits, coils and displays; if needed, contact the free support.
See also
- Cleopatra (Gottlieb, 1977)
- Sinbad (Gottlieb, 1978)
- Dragon (Gottlieb, 1978)
- Charlie's Angels (Gottlieb, 1978)
