Playboy (Bally, 1978): faults and replacement boards (Bally MPU)
Does your Bally Playboy no longer start, have its displays off, stuck targets 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 battery that has leaked. Good news: the BallyFA replacement MPU board, Plug & Play and battery-free, brings your machine back to life.
Playboy (Bally, 1978): overview
Released in 1978 on the Playboy magazine theme, Playboy is one of Bally's great solid state hits. Designed by Jim Patla (artwork by Paul Faris), it uses the Bally MPU from the AS-2518 series.
- Manufacturer: Bally
- Year: 1978
- Electronic system: Bally MPU (AS-2518)
- Type: electronic pinball (solid state)
- Theme: Playboy
Common faults (Bally / Stern)
On Bally and Stern microprocessor machines (1977-1985), recurring faults come from ageing: leaking battery on the MPU (corrosion of traces and sockets around U10/U11, the no.1 cause of dead boards), tired 6821 PIAs (U10/U11) (oxidised legs, impossible start-up), 5101 RAM and sockets to replace, MPU/power connectors oxidised or burnt (look for heat marks), displays with missing segments, and a power/driver board (rectifier, fuses, coil transistors) to rework.
Issues specific to Playboy (forum feedback)
- Leaked battery on the MPU: corrosion around U10/U11, to be dealt with as a priority.
- Drop targets that don't reset: often the outhole switch or the target switches to check.
- Displays off or partial: the displays' power supply and MPU to check.
- Runaway or dead coils: driver board (transistors, fuses) to rework.
- Oxidised or burnt connectors: to replace (repin) to make the machine reliable.
- Blowing fuses: look for a shorted rectifier or coil.
Replacement boards compatible with Playboy
- BallyFA — replacement MPU board (battery-free).
- BallyDri — power supply + driver.
- BallyLa_60 — lamp driver.
📚 Further reading: Guide: which MPU board for a Bally / Stern (1977-1985)?
The BallyFA replaces the original MPU board (start-up, logic, battery-free memory) and does away with the battery, the no.1 cause of corrosion. For the coils and the power supply, the BallyDri takes over; the lamps via the BallyLa_60. Plug & Play installation, battery-free, free support. Contact us.
FAQ — Playboy Bally
My Playboy no longer starts.
Check the battery and the corrosion around U10/U11. The BallyFA replaces the MPU and works without a battery.
My targets no longer reset.
Often an outhole or target switch; on the logic side, the BallyFA makes switch reading and coil control reliable.
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 no.1 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 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 damage on your Playboy MPU, especially around U10/U11; remove the battery if still present.
- Power: measure the 5 V and check that it reaches the MPU (rework the power/rectifier board and the fuses if the voltage drops).
- Grounds and connectors: rework the oxidised or burnt MPU/power connectors (heat marks) between the boards.
- MPU components: check the 6821 PIAs (U10/U11) and the 5101 RAM, often tired or corroded by the battery.
- 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; reminder: the BallyFA replaces the MPU and boots without a battery. If needed, contact our free support.
