Fireball Classic (Bally, 1985): faults and replacement boards (Bally MPU)
Is your Bally Fireball Classic refusing to boot, stuck with a silent multiball, dead displays or runaway coils? 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. Good news: the BallyFA replacement MPU board, Plug & Play and battery-free, gives your machine a second life.
Fireball Classic (Bally, 1985): overview
Released in 1985, Fireball Classic is a solid-state reinterpretation of the famous Fireball, with a central spinning disc and multiball. It uses the AS-2518 series Bally MPU.
- Manufacturer: Bally
- Year: 1985
- Electronic system: Bally MPU (AS-2518)
- Type: solid-state pinball, multiball, spinning disc
- Theme: Fireball / fantasy
Common faults (Bally / Stern)
On Bally and Stern microprocessor machines (1977-1985), recurring faults come from ageing: a leaking battery on the MPU (corroded traces and sockets around U10/U11, the number one cause of dead boards), tired 6821 PIAs (U10/U11) (oxidised pins, no boot), 5101 RAM and sockets to be replaced, MPU/power connectors oxidised or burnt (look for heat marks), displays with missing segments, and the power supply/driver board (rectifier, fuses, coil transistors) needing rework.
Fireball Classic-specific issues (forum feedback)
- Temperamental central spinning disc: check the motor, coil and disc switch.
- Multiball won't start: check the lock and trough switches.
- Leaking battery on the MPU: corrosion around U10/U11.
- Dead or partial displays: check the display and MPU power supply.
- Runaway or dead coils: rework the driver board (transistors, fuses).
- Oxidised or burnt connectors: replace (re-pin) them to make the machine reliable.
Replacement boards compatible with Fireball Classic
- BallyFA — replacement MPU board (battery-free).
- BallyDri — power supply + driver.
- BallyLa_60 — lamp driver.
📚 To go further: Guide: which MPU board for a Bally / Stern (1977-1985)?
The BallyFA replaces the original MPU board (boot, logic, multiball control, battery-free memory) and removes the battery, the number one cause of corrosion. For coils and power, the BallyDri takes over; for lamps, the BallyLa_60. Plug & Play installation, battery-free, free support. Contact us.
FAQ — Fireball Classic Bally
My multiball no longer starts.
Often the lock or trough switches; on the logic side, the BallyFA makes coil and multiball control reliable.
My Fireball Classic won't boot.
Check the battery and corrosion around U10/U11. The BallyFA replaces the MPU and works without a battery.
Is the BallyFA compatible with my Bally?
Yes, for Bally/Stern microprocessor machines (1977-1985). If in doubt, contact us.
Should I keep the original battery?
No. The BallyFA works without a battery and removes the number one cause of corrosion.
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 settings and high scores?
Yes. Modern replacement boards use non-volatile memory: no battery, no corrosion, and settings are kept when powered off.
Step-by-step diagnosis
- Powered off, visual inspection: look for any battery or corrosion marks on your Fireball Classic's MPU, especially around U10/U11; remove the battery if it is still present.
- Power supply: measure the 5 V and check it reaches the MPU (check the rectifier and rework tired solder joints if the voltage drops).
- Grounds and connectors: check the grounds and re-pin oxidised or burnt Molex connectors between MPU, power supply and driver.
- Key components: check the 6821 PIAs (U10/U11) and the RAM, whose sockets oxidise and prevent booting.
- Displays and multiball: never plug or unplug a display while powered on; check the multiball lock and trough switches.
- Final test: check boot, credits, coils, spinning disc and displays; if needed, contact free support. Reminder: the BallyFA replaces the original MPU, battery-free.
