Monte Carlo (Gottlieb, 1987): faults and replacement boards System 80B

Does your Gottlieb Monte Carlo only boot correctly with the fluorescent tube removed, does a display go dark, does the general illumination drop out or does the game reset? These symptoms are typical of Gottlieb System 80B pinball machines, whose original boards (MPU, Driver, power supply, sound) are now over 40 years old. Good news: modern replacement boards, Plug & Play and battery-free, give your machine a second life.

Monte Carlo (Gottlieb, 1987): overview

Released in 1987, Monte Carlo is a System 80B pinball machine with a casino and auto racing theme. It offers the alphanumeric displays and a characteristic « Spin-A-Ball » mechanism.

• Manufacturer: D. Gottlieb & Co.
• Year: 1987
• Electronic system: Gottlieb System 80B
• Type: solid state pinball machine, alphanumeric displays
• Theme: casino / auto racing

Common faults (System 80B)

The System 80B uses alphanumeric displays and an MPU with battery-backed 5101 RAM. Recurring faults: leaking battery on the MPU (corrosion and loss of the 5101 memory), unstable power supply (the original trim pot struggles to hold 5 V and 12 V), cracked solder joints (notably on the CPU daughter card), inter-board connectors needing re-pinning, deficient grounds (ground mods essential), dark displays if a single bit fails to pass from the MPU to the display, and startup disrupted by the backbox fluorescent tube starter.

Issues specific to Monte Carlo (forum feedback)

• Correct boot only with the fluorescent tube removed: the backbox tube starter disrupts startup (scrambled displays, sound that won't start, stuck lamps or coils). Removing the tube or the starter solves the problem.
• Lower display going dark after boot: pinch the sides of the Molex pins to ensure contact.
• MPU that won't boot: daughter card (fractured solder joints), ROM, RIOT U4/U5/U6, faulty 5101 or 6502.
• GI dead: a fuse blows during the T relay test and cuts all the upper general illumination.
• Spin-A-Ball inoperative + coils: check the continuity of the coils up to the MPU if the connectors are corroded.

Replacement boards compatible with Monte Carlo

• GottFA80_Plus (Light) — all-in-one CPU + Driver + power supply board, without sound.
• GottFA80_Plus (Full) — same with integrated sound board (80B audio limited to a few titles).
• Gosof — replacement sound board for System 80 and 80A (80B support currently limited to a few titles).
• Godri80 — replacement Driver board.
• Lisy80 — CPU board + web diagnostics.
• GoPOP80 — bumper driver board (MA-922).

System 80B specifics: favour the GottFA80_Plus Light — the 80B is covered on the CPU/MPU side. On the audio side, support is for now limited to a few titles (Bounty Hunter, Chicago Cubs Triple Play, Tag Team); for other System 80B machines, keep and repair the original sound board and contact us (an audio solution is in preparation).

Plug & Play installation, battery-free, free tutorials and support. Contact us.

FAQ — Monte Carlo Gottlieb

My Monte Carlo only boots well if I remove the fluorescent tube.
It's the tube starter that interferes with startup. Remove the tube or the starter; a replacement MPU also makes the boot reliable.

The lower display goes dark after boot.
Pinch the Molex pins to restore contact. A new MPU then eliminates these glitches.

My GI goes out completely.
Check the fuse linked to the T relay. The Godri80 Driver board replaces the driver stage if an output is at fault.

And what about 80B sound?
Audio support is for now limited to a few titles (Bounty Hunter, Chicago Cubs Triple Play, Tag Team). For Monte Carlo, keep and repair the original sound board and contact us; a solution is in preparation.

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

1. Power off, visual inspection: look for any battery trace or corrosion on your Monte Carlo's MPU; remove the NiCad battery if still present.
2. Power supply: measure the 5 V and check it reaches the MPU (re-solder the regulator or Q1 if the voltage drops).
3. Grounds: apply the "ground mods" between the boards (CPU, Driver, power supply, sound).
4. Connectors: re-pin the oxidized Molex connectors, especially the MPU↔Driver link.
5. Displays: never connect or disconnect a display while powered on; test with a known-good display.
6. Final test: check startup, credits, coils and displays; if needed, contact free support.

See also

• Gold Wings (Gottlieb, 1986)
• Amazon Hunt III (Gottlieb, 1987)
• Spring Break (Gottlieb, 1987)
• Arena (Gottlieb, 1987)

Sources & further reading

• Pinside Forum — Monte Carlo
• IPDB — Internet Pinball Database
• OPDB — Open Pinball Database