Lectronamo (Stern, 1978) : pannes et carte de remplacement (MPU Stern M-100)
Is your Stern Lectronamo no longer starting, silent, showing dead displays or runaway coils? 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 leaking battery. A battery-free replacement board gives your machine a second life.
Lectronamo (Stern, 1978): overview
Released in 1978 on a futuristic theme, Lectronamo is a solid-state pinball from Stern (design by Mike Kubin) fitted with the SB-100 sound board. It uses the Stern M-100 MPU board, distinct from the Bally boards.
- Manufacturer: Stern
- Year: 1978
- Electronic system: Stern M-100 MPU (+ SB-100 sound board)
- Type: electronic pinball (solid state)
- Theme: futuristic / electronic
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 chips (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.
Lectronamo-specific issues (forum feedback)
- No more sound: the (specific) SB-100 sound board is diagnosed separately.
- Battery leaked on the MPU: trace corrosion, to be treated as a priority.
- Does not start: the RAM or logic chips of the M-100 MPU to be checked.
- Dead or partial displays: the display power supply and MPU to be checked.
- Runaway or dead coils: the driver board (transistors, fuses) to overhaul.
- Oxidised or burnt connectors: to be replaced to make the machine reliable.
Replacement board for the Lectronamo (Stern M-100)
Important: the Lectronamo 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 your board references, and we will point you to the right solution (battery-free, free support).
📚 To go further: Guide: which MPU board for a Bally / Stern (1977-1985)?
FAQ — Lectronamo (Stern)
Which replacement board for my Lectronamo?
The Lectronamo uses a Stern M-100 MPU; contact us with your board references for the right solution (battery-free).
My Lectronamo has no sound anymore.
The SB-100 sound board is diagnosed separately; contact us for troubleshooting.
My Lectronamo no longer starts.
First check the battery and corrosion on the MPU: it is the number-one cause of dead boards.
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 Lectronamo, 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.
