Lost World (Bally, 1978): Troubleshooting and Bally MPU Replacement Boards
Is your Lost World by Bally not starting, has no sound, dead displays, or stuck solenoids? These symptoms are typical of Bally microprocessor pinball machines whose original MPU board is now over 40 years old and almost always suffers from a leaking battery. The good news: the BallyFA replacement MPU board, Plug & Play and battery-free, brings your machine back to life.
Lost World (Bally, 1978): Overview
Released in 1978, Lost World is a Bally machine (over 10,000 units) and one of the first to replace chimes with electronic sound, with an alphanumeric display. It uses the Bally MPU board (AS-2518 series).
- Manufacturer: Bally
- Year: 1978
- Electronic system: Bally MPU (AS-2518)
- Type: solid state, electronic sound
- Theme: lost world / prehistory
Common Issues (Bally MPU)
On Bally microprocessor pinball machines (1977-1985), recurring failures stem from aging: leaking battery on the MPU (corrodes traces and sockets around U10/U11 — the #1 cause of dead boards), worn PIA 6821 chips (U10/U11) (oxidized pins, machine won't boot), failed 5101 RAM and sockets, oxidized or burnt MPU/power connectors (look for heat marks), displays with missing segments, and power supply/driver board (rectifier, fuses, solenoid transistors) needing attention.
Lost World-Specific Issues (Forum Reports)
- Leaking battery on MPU: corrosion around U10/U11 — treat first.
- No sound: one of Bally's first electronic sound boards, diagnosed separately.
- Alphanumeric displays off or partial: display power supply and MPU to check.
- Erratic or dead solenoids: driver board (transistors, fuses) to refurbish.
- Oxidized or burnt connectors: replace to make the machine reliable.
- Blowing fuses: look for a shorted rectifier or solenoid coil.
Compatible Replacement Boards for Lost World
- BallyFA — replacement MPU board (battery-free).
- BallyDri — power supply + driver board.
- BallyLa_60 — lamp driver board.
📚 Learn more: Guide: Which MPU board for a Bally (1977-1985)?
The BallyFA replaces the original MPU board (startup, game logic, battery-free memory) and eliminates the battery — the #1 cause of corrosion. The early electronic sound board is diagnosed separately. For solenoids and power, the BallyDri takes over; lamps via the BallyLa_60. Installation is Plug & Play, battery-free, with free support. Contact us.
FAQ — Lost World Bally
My Lost World has no sound.
It uses one of Bally's first electronic sound boards, diagnosed separately; the BallyFA stabilizes the MPU and game logic.
My Lost World won't start.
Check the battery and corrosion around U10/U11. The BallyFA replaces the MPU and runs without a battery.
Is the BallyFA compatible with my Bally?
Yes, for all Bally microprocessor machines (1977-1985). If in doubt, contact us.
Do I need to keep the original battery?
No. The BallyFA runs without a battery and eliminates the #1 cause of corrosion.
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 Lost World; remove the original battery if still present.
- Power supply: measure voltages (especially 5V) and verify they reach the MPU; check the rectifier and power board fuses.
- MPU components: inspect the PIA 6821 chips (U10/U11) and the 5101 RAM, often corroded by battery leakage.
- Connectors: re-pin oxidized or burnt connectors, especially between the MPU and power supply.
- Displays: check display power supply; test with a known good display.
- Final test: verify startup, credits, solenoids, and displays; the BallyFA replaces the MPU battery-free; 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 MPU board for a Bally (1977-1985)?
