KISS (Bally, 1979): faults and replacement boards (Bally MPU)
Does your Bally KISS no longer start, have tired connectors, runaway coils or displays off? 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.
KISS (Bally, 1979): overview
Released in 1979 on the theme of the rock band KISS, KISS is one of Bally's most famous solid state pinball machines. It uses the Bally MPU from the AS-2518 series.
- Manufacturer: Bally
- Year: 1979
- Electronic system: Bally MPU (AS-2518)
- Type: electronic pinball (solid state)
- Theme: rock band KISS
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 KISS (forum feedback)
- Connectors to repin: on these Bally machines, most switch problems come from original connectors that need redoing.
- Orange wire from rectifier to driver board: faulty contact to repin (coil power supply).
- Won't start / stays in diagnostics: failing RAM that prevents boot and attract mode.
- Leaked battery on the MPU: corrosion around U10/U11.
- Runaway or dead coils: driver board (transistors, fuses) to rework.
- Displays off or partial: the displays' power supply and MPU to check.
Replacement boards compatible with KISS
- 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, memory and RAM battery-free) and does away with the battery, the no.1 cause of corrosion, as well as the dependence on the old RAM. 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 — KISS Bally
My KISS won't start / stays in diagnostics.
Often failing RAM. The BallyFA replaces the MPU and its memory, and starts without a battery.
Switches or coils are temperamental.
Repin the original connectors (including the orange wire from the rectifier). On the board side, the BallyFA and the BallyDri make the whole thing 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 trace on the MPU board of your KISS; remove the original battery if it is still present.
- Power supply: measure the voltages (especially 5 V) and check they reach the MPU; check the rectifier and the fuses on the power board.
- MPU components: check the 6821 PIAs (U10/U11) and the 5101 RAM, often oxidised by the battery.
- Connectors: repin the oxidised or burnt connectors, especially between the MPU and the power supply.
- Displays: check the displays' power supply; test with a known-good display.
- Final test: check start-up, credits, coils and displays; the BallyFA replaces the MPU without a battery; if needed, contact free support.
