Support this Pinball Repair Website & PHoF. Please purchase the pinrepair.com/top
Repairing Bally Electronic Pinball Games
from 1977 to 1985.
Copyright 1999-2007 all rights reserved.
This document is a repair guide for Bally electronic pinball
games made from 1977 to 1985. Since Stern electronic pinball
games use nearly identical electronics, these games
are covered too.
Internet Availability of this Document.
Updates of this document are available for no cost at
if you have Internet access. This document is three parts
(part one is here, and
part two is here, and part three is
IMPORTANT: Before Starting!
IF YOU HAVE NO EXPERIENCE IN CIRCUIT BOARD REPAIR,
YOU SHOULD NOT TRY TO FIX YOUR OWN PINBALL GAME!
Before you start any pinball circuit board repair,
review the document at http://pinrepair.com/begin,
which goes over the basics of circuit board repair. Since
these pinball repair documents have been available, repair facilities are reporting a
dramatic increase in the number of ruined ("hacked") circuit boards sent in for repair.
Most repair facilities
will NOT repair your circuit board after it has been unsuccessfully repaired ("hacked").
If you aren't up to repairing pinball circuit boards yourself or need pinball parts
or just want to buy a restored game, I recommend seeing the
suggested parts & repair sources web page.
Table of Contents
- Experience, Schematics, Manuals
- Necessary Tools
- Parts to have On-Hand
- Game List
- Lubrication Notes
- The Circuit Boards
- Voltage Test Points on the Boards and the Power Train
- Fuse Values/Usage & Power Supply Power Distribution
2. Before Turning the Game On:
- Check the Coil Resistance
- Removing the MPU Battery and Fixing Corrosion
- The Power Supply - Blown Fuses, Bridges, etc.
- Upgrading the Voltage Regulator/Solenoid Driver Board
- Upgrading the Ground on the MPU Board
- Pre Power-On Voltage Checks
- Setting Free Play
3. When Things Don't Work:
- Making a MPU test fixture
- Fixing the MPU (LED flashes and the such)
- Game ROMs, EPROMs, and Jumper - the Basics
- -35 MPU Game ROMs, EPROMs, and Jumpers
- -17 MPU Game ROMs, EPROMs, and Jumpers
- Stern M-200 MPU Jumpers (using a Stern M-200 in a Bally Game)
- Converting a -133 MPU (Baby Pacman) to a -35 MPU
- The Built-In Diagnostics/Bookkeeping
- Coils: Locked-on, Sporadic, or Not Working (Solenoid Driver board)
- Lamps: Locked-on or Not Working Feature Lamps (Lamp Driver board)
- Solenoid Expander Board Problems
- Auxiliary Lamp Driver Board Problems
- Switches and the Switch Matrix
- High Voltage Section Problems (No Score Display Power)
- Score Display Replacement and Fixes
- Reset or Lockup Power Problems
- Sound Board Problems
- Miscellaneous Problems and Fixes
Bibliography and Credit Where Credit is Due.
Many of the ideas in this repair guide are not original.
Lots of people contributed to this document, and I just want to
say, "thanks!" Below are a list of
the resources used in the development of this guide. Some resources/people
may have been innocently left out. If this is the case, and an idea
is here that was originally yours, please notify me and I
will make sure to give you credit!
Some people question whether I wrote all this material myself. I did, but of
course like everyone, my repair techniques and ideas are gathered
not only from my own experience, but from work that
others in this hobby do and share at shows, on the
internet, etc. So if you're the originator of some
cool trick or tip in this document, and I'm not giving due credit,
just let me know and I'll add you to the list of contributors above.
- "Electronic Pinball Games Repair Procedures", Bally,
part number F.O.560-3, fourth edition, dated October 1, 1981.
- Jerry Clause,
who provided tons of tips and tricks.
- Tom Callahan and his web site at www.repairconnection.com.
- Mr. Johnson and his web site at www.aros.net/~rayj/action/tech.
Ray's postings and tips were most helpful.
- Duncan Brown. Duncan provided lots of tips and tricks.
- Rob Hayes, who's advice and proof reading were very appreciated.
- David Gersic, who also did proof reading and provided some tips.
- John Robertson and his posts & tips helped mucho grande.
- Dwight Elvey for his posts, tips and tricks.
- A. Reizman for his amazing wealth of knowledge.
- Pinball Liz Tech Reprints #1 to #6, August 1995 to August 1996,
for their tips and tricks.
Why is this Document Available?
There has been TONS of information and fixes published for the 1977 to 1985
Bally electronic pinball games. There's no complete information of "here's what to do"
in its entirety. This guide should fill that void.
* Go to the Bally Repair Guide Part 1
* Go to the Bally Repair Guide Part 2
* Go to the Bally Repair Guide Part 3
* Go to the Pin Fix-It