Evel Knievel (Bally, 1977): Troubleshooting and Bally MPU Replacement Boards
Is your Evel Knievel by Bally powering on but not starting, has reset problems, cracked solder joints, or a dead flipper? 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. The good news: the BallyFA replacement MPU board, Plug & Play and battery-free, brings your machine back to life.
Evel Knievel (Bally, 1977): Overview
Released in 1977, Evel Knievel is one of Bally's very first solid-state pinball machines (also released in an electromechanical version); this covers the microprocessor version. It uses the Bally MPU board (AS-2518 series).
- Manufacturer: Bally
- Year: 1977
- Electronic system: Bally MPU (AS-2518)
- Type: solid state
- Theme: motorcycle stuntman / Evel Knievel
Common Issues (Bally MPU)
On Bally microprocessor pinball machines (1977-1985), recurring failures stem from aging: leaking battery on the MPU (corrodes traces and sockets around U10/U11 — the #1 cause of dead boards), worn PIA 6821 chips (U10/U11) (oxidized pins, machine won't boot), failed 5101 RAM and sockets, oxidized or burnt MPU/power connectors (look for heat marks), displays with missing segments, and power supply/driver board (rectifier, fuses, solenoid transistors) needing attention.
Evel Knievel-Specific Issues (Forum Reports)
- Powers on but won't start: often a failed PIA 6821 (U10) or battery corrosion; diagnose with a PIA tester.
- Solenoids and resets: coil and reset problems tied to the driver board.
- Cracked solder joints on the driver board: rework them; wires pulled out of their female connector need re-crimping.
- A flipper that doesn't work or silent chimes: check the coil, switch, and sound driver.
- Leaking battery on MPU: corrosion around U10/U11.
- Oxidized connectors: replace to stabilize the machine.
Compatible Replacement Boards for Evel Knievel
- BallyFA — replacement MPU board (battery-free).
- BallyDri — power supply + driver board.
- BallyLa_60 — lamp driver board.
📚 Learn more: Guide: Which MPU board for a Bally (1977-1985)?
The BallyFA replaces the original MPU board (startup, game logic, battery-free memory) and eliminates the battery — the #1 cause of corrosion. For solenoids and power, the BallyDri takes over; lamps via the BallyLa_60. Installation is Plug & Play, battery-free, with free support. Contact us.
FAQ — Evel Knievel Bally
My Evel Knievel powers on but won't start.
Often a failed PIA 6821 (U10) or battery corrosion. The BallyFA replaces the MPU (including the PIAs) and runs without a battery.
The driver board has cracked solder joints.
Rework the joints and re-crimp any pulled wires. On the power side, the BallyDri (power supply + driver) replaces the aging board.
Is the BallyFA compatible with my Bally?
Yes, for all Bally microprocessor machines (1977-1985). If in doubt, contact us.
Do I need to keep the original battery?
No. The BallyFA runs without a battery and eliminates the #1 cause of corrosion.
How long does installation take?
Installation is Plug & Play: just a few minutes, no soldering required, with tutorials and free support.
Does a battery-free board retain settings and high scores?
Yes. Modern replacement boards use NVRAM: no battery, no corrosion, and settings are preserved when powered off.
Step-by-Step Diagnostics
- With power off, visual inspection: look for any signs of battery leakage or corrosion on the MPU of your Evel Knievel; remove the original battery if still present.
- Power supply: measure voltages (especially 5V) and verify they reach the MPU; check the rectifier and power board fuses.
- MPU components: inspect the PIA 6821 chips (U10/U11) and the 5101 RAM, often corroded by battery leakage.
- Connectors: re-pin oxidized or burnt connectors, especially between the MPU and power supply.
- Displays: check display power supply; test with a known good display.
- Final test: verify startup, credits, solenoids, and displays; the BallyFA replaces the MPU battery-free; if needed, contact free support.
Useful Guides
- How much does pinball machine repair cost? A price guide
- How much is my pinball machine worth? Value and estimation
- Pinball machine leg sizes: the complete guide
- Which MPU board for a Bally (1977-1985)?
