Dragon (Gottlieb, 1978): faults and System 1 replacement boards
Does your Dragon (Gottlieb, 1978) lose its credits, stay stuck on a continuous tone or no longer start properly? This Gottlieb pinball with a medieval-fantasy theme runs on System 1. Here are the typical faults reported on the forums and the battery-free replacement solutions.
Dragon overview
Released in 1978, the Dragon is a Gottlieb solid-state pinball built on System 1. Its medieval-fantasy world features a dragon and a heroic-fantasy atmosphere.
- Manufacturer: Gottlieb
- Year: 1978
- System: Gottlieb System 1
- Type: solid state (alphanumeric displays)
- Theme: medieval-fantasy, dragon

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.

Dragon-specific problems (forums)
- Phantom credits: you insert 4 credits, start the game and the 3 remaining credits vanish; the counter can also freeze on an impossible value (above 15).
- Corrupted credit counter: after a loss of CMOS RAM power, the credit display no longer matches reality and simply clearing the audits is not enough.
- Stuck sound: a single continuous tone comes from the speaker, sometimes even after replacing the sound board — a power-supply and connections lead to investigate.
- Insufficient 5 V: make sure the power supply actually delivers 5 V and that this voltage reaches the MPU; below 5 V, behaviour becomes erratic.
- Missing protections: add the recommended fuses and check the protection diodes, often absent or tired.
- Battery and connectors: remove the MPU battery and re-pin the MPU↔Driver connector to eliminate intermittent faults.
Dragon-compatible replacement boards
The Dragon 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 Dragon. Plug & Play installation, battery-free, free support.
FAQ — Dragon Gottlieb
What year was the Dragon released?
In 1978. It's a Gottlieb solid-state pinball on the System 1 platform.
Why does my Dragon lose its credits?
It's typically the CMOS RAM no longer holding the information, often combined with an unstable 5 V supply. A battery-free replacement board, together with the ground mods, fixes the problem for good.
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 Dragon?
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 Dragon; 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)
- Joker Poker (Gottlieb, 1978)
- The Incredible Hulk (Gottlieb, 1979)