Stars (Stern, 1978) : pannes et carte de remplacement (MPU Stern M-100)
Is your Stern Stars no longer starting, with its displays dead or coils running wild? These symptoms are typical of Stern microprocessor pinballs (M-100 MPU), whose original board is now over 40 years old and almost always suffers from a leaked battery. A battery-free replacement board gives your machine a second life.
About the Stars (Stern, 1978)
Released in 1978 on a stars-and-space theme, Stars is a solid-state pinball from Stern (a chimes machine). It uses the Stern M-100 MPU board, distinct from the Bally boards.
- Manufacturer: Stern
- Year: 1978
- Electronic system: Stern M-100 MPU
- Type: solid-state pinball (chimes)
- Theme: stars / space
Common faults (Stern M-100)
On Stern M-100 microprocessor machines (1977-1979), the recurring faults come from ageing: battery leaking on the MPU (trace corrosion, the number-one cause of dead boards), tired logic circuits (RAM, PIA, no start-up), oxidised or burnt MPU/power connectors (look for heat marks), displays with missing segments, and a power/driver board (rectifier, fuses, coil transistors) to overhaul.
Stars-specific issues (forum feedback)
- Leaked battery on the MPU: trace corrosion, to be dealt with first.
- Does not start: RAM or logic circuits of the M-100 MPU to check.
- Displays dead or partial: display power supply and MPU to check.
- Coils running wild or inert: driver board (transistors, fuses) to overhaul.
- Oxidised or burnt connectors: to be replaced to make the machine reliable.
- Silent chimes: chime coils and their drivers to check.
Replacement board for Stars (Stern M-100)
Important: Stars uses a Stern M-100 MPU board, different from the Bally board. The most suitable replacement board is determined case by case: contact us with the references of your boards, and we will tell you the right solution (battery-free, free support).
📚 To go further: Guide: which MPU board for a Bally / Stern (1977-1985)?
FAQ — Stars Stern
Which replacement board for my Stars?
Stars uses a Stern M-100 MPU; contact us with the references of your boards for the right solution (battery-free).
My Stars no longer starts.
First check the battery and corrosion on the MPU: it is the number-one cause of dead boards.
Some coils run wild or do not respond.
On the power side, the driver board is to blame (transistors, fuses); contact us for the diagnosis.
Should I keep the original battery?
No: a battery-free board 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 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 marks on the MPU of your Stars, especially around U10/U11; remove the battery if it is still present.
- Power supply: measure the 5 V and check that it reaches the MPU; check the bridge rectifier and the power-supply fuses.
- Grounds: redo the grounds between the MPU, the power/driver board and the display.
- Connectors: re-pin the oxidised Molex connectors, especially the MPU↔power link.
- 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; the BallyFA replaces the MPU, battery-free. If needed, contact the free support.
