Excalibur (Gottlieb, 1988): Troubleshooting and System 80B Replacement Boards
Is your Excalibur by Gottlieb has faulty drop targets, sound cutting out, blank displays, or keeps resetting? These symptoms are typical of Gottlieb System 80B pinball machines whose original boards (MPU, driver, power supply, sound) are now over 40 years old. The good news: modern replacement boards, Plug & Play and battery-free, bring your machine back to life.
Excalibur (Gottlieb, 1988): Overview
Released in 1988, Excalibur is a large-format System 80B pinball machine with a medieval King Arthur and sword-in-the-stone theme, featuring alphanumeric displays.
- Manufacturer: D. Gottlieb & Co.
- Year: 1988
- Electronic system: Gottlieb System 80B
- Type: solid state, alphanumeric displays
- Theme: medieval / King Arthur
Common Issues (System 80B)
System 80B machines use alphanumeric displays and a 5101 RAM-based MPU backed by a battery. Recurring failures include: leaking battery on the MPU (corrosion and loss of the 5101 memory), unstable power supply (the original trim pot struggles to maintain 5V and 12V), cracked solder joints (especially on the CPU daughter card and the LM338K regulator), inter-board connectors needing re-pinning, poor grounds (ground mods are essential), dead displays if even a single data bit fails between the MPU and display, and startup disrupted by the fluorescent tube starter in the backbox.
Excalibur-Specific Issues (Forum Reports)
- Drop target bank failure: the exposed common wire on the bank can break while still appearing connected.
- Sound cutting out: Gottlieb header pins between the sound board and MPU lose voltage; re-pin the sound board and auxiliary power supply.
- Sound diagnosis: firmly press the chips on the sound board while the game is on to locate a bad contact.
- Blank displays / grounds: properly connecting grounds to the transformer often restores the display.
- Transistors and edge connectors: tighten transistors and clean dirty edge connectors.
Compatible Replacement Boards for Excalibur
- GottFA80_Plus (Light) — all-in-one CPU + driver + power supply board, without sound.
- GottFA80_Plus (Full) — same all-in-one board with integrated sound (80B audio currently limited to select titles).
- Gosof — replacement sound board for System 80 and 80A (80B support currently limited to select titles).
- Godri80 — replacement driver board.
- Lisy80 — CPU board + web-based diagnostics.
- GoPOP80 — pop bumper driver board (MA-922).
System 80B note: we recommend the GottFA80_Plus Light — 80B is covered on the CPU/MPU side. On the audio side, support is currently limited to select titles (Bounty Hunter, Chicago Cubs Triple Play, Tag Team); for other System 80B games, keep and repair the original sound board and contact us (an audio solution is in development).
Installation is Plug & Play, battery-free, with tutorials and free support. Contact us.
FAQ — Excalibur Gottlieb
A drop target bank is unresponsive.
Check the exposed common wire, which may have broken. Then check the switches; a new MPU stabilizes the reading.
The sound cuts out.
Re-pin the sound board and auxiliary power supply; repair the original sound board. For 80B audio, support is limited to select titles — contact us.
My displays are blank.
Properly connect the grounds to the transformer and re-seat the ribbon cable. A replacement MPU stabilizes the display interface.
Do I need a wiring extension for the board on 80B?
Often yes: on Excalibur, the original display ribbon can be a bit short, and the backbox fluorescent tube may need slight repositioning to clear the GottFA80 Light. Our tutorials and free support will guide you.
What about 80B sound?
80B audio support is currently limited to select titles (Bounty Hunter, Chicago Cubs Triple Play, Tag Team). For Excalibur, keep and repair the original sound board and contact us; a solution is in development.
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 Excalibur; remove the NiCad battery if still present.
- Power supply: measure the 5V rail and verify it reaches the MPU (re-solder the voltage regulator or Q1 if voltage drops).
- Grounds: apply ground mods between the boards (CPU, driver, power supply, sound).
- Connectors: re-pin oxidized Molex connectors, especially the MPU-to-driver board connection.
- Displays: never connect or disconnect a display while powered on; test with a known good display.
- Final test: verify startup, credits, solenoids, and displays; 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 Gottlieb System 80, 80A or 80B?
See Also
- Robo-War (Gottlieb, 1988)
- Bad Girls (Gottlieb, 1988)
- Big House (Gottlieb, 1989)
- TX-Sector (Gottlieb, 1988)
