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1 Introduction

Pinball test fixtures were designed to aid in the testing and repair of circuit boards in pinball machines. These fixtures were originally used by distributors who performed repairs and operators who serviced their own equipment. These fixtures are now commonly utilized by individuals experienced with board repair and who perform repairs frequently for games.

Most test fixtures primarily emulate a pinball machine's lamps, solenoids, displays, switches, and sounds. There are also various test sequences available, plus the ability to perform repetitious tests in order to "burn-in" a board.

The downside to these fixtures is that they are big, bulky, and tend to be rather expensive. In some cases, there is little or no documentation for the fixtures. Sometimes, fixtures were modified to accommodate boards, displays, or features that they were not originally intended to support. There is also little or no documentation on these modifications.

Since these test fixtures are designed to emulate the guts of a pinball machine, some collectors/technicians have built their own test fixtures using the guts of actual pinball machines.

Additionally, there are now various modern diagnostic tools available to help aid with testing components, circuit boards, and performing diagnostics while in-game or on the bench.

2 Test Fixtures

2.1 Bally/Stern (Classic)

Bally took a different approach than most other manufacturers and built four discrete test fixtures for testing individual boards, which are commonly known as "Bally brown box testers".

2.1.1 Bally MPU Test Fixture

This test fixture can test Bally MPUs, however, the helpfulness of this test fixture in troubleshooting many problems is limited.

2.1.2 Bally Lamp Board Test Fixture

This test fixture can test both classic Bally and Stern lamp driver boards. There is supposedly a later modification that can be performed on the test fixture in order to be able to test aux lamp boards.

Bally Brown Test Fixture Schematics (Complete Set)

2.1.3 Bally Solenoid Driver Board Test Fixture

This test fixture can test both classic Bally and Stern solenoid driver boards. It can also test early Bally sound boards, but that may require modifications.

A YouTube video demonstrating a successful solenoid driver board solenoid test, and a separate video for a voltage test.
A YouTube video demonstrating a successful -51 sound board test using a Space Invaders sound ROM.

Documentation

2.1.3.1 Modified Solenoid Driver Board Test Fixture for Testing Sound Boards

This modification is based on the FO 640 instructions. The instructions to modify the PCB are fairly straight forward, but the wiring modifications may be a little difficult to understand. Below are photos of a modified test fixture. Note the addition of the terminal strip near the speaker for the added resistor.

Exterior Photos
Test fixture with solenoid driver board
Test fixture with sound board
Connector for sound boards

Modified PCB Photos

Modified Interior Photos
PCB Connector J1
PCB Connector J2
PCB Connector J3

2.1.4 Bally Display Test Fixture

This test fixture can test 6-digit Bally and Stern displays, and can be modified to also test 7-digit displays.

2.1.4.1 7-Digit Modification

Modifying the display test fixture to accommodate 7-digit displays involves adding some jumper wire, making some trace cuts, and couple components.

Parts needed:

30 awg wire
18 awg wire
20kohm 1/4 resistor
SPDT switch
Heat shrink wire wrap.

First, a couple of modifications will need to be made to the wiring between the .156" board connector and the .156" display connector.

The original .156" board connector. Note the position of the red wire with white bands.

Removed the red wire with the white bands and insert it into the open spot in the connector. Then, add a new wire in the spot from which the red wire was removed.

The modified .156" board connector. Note the position of the red wire with white bands and the new white wire.

On the .156" display connector, add the white wire and a jumper wire between the two pins. Two wires will need to be crimped into one of the pins.

The modified .156" display connector. Note the addition of the white wire and jumper wire.

On the .100" board connector, add two lead wires. These will be connected to the new SPDT switch. A new 1/4" hole can be drilled in the metal plate to add the switch.

The modified .100" board connector. Note the addition of the two wires.

Note the addition of the two wires and switch.

Note the addition of the new switch on the control panel.

Next, on the board, cut the indicated traces, add the resistor, and add the jumper wires. When adding the resistor, be sure to put heat shrink on both leads to make sure those leads don't accidentally make contact with anything they aren't supposed to.

When using the test fixture, flipping the switch to the wrong setting will not cause any damage--it will simply interfere with the display blanking signal depending upon the header pin arrangement of the type/version of the display being tested and what the unused pins on the 6-digit display are tied to. Other than that, there are no ill effects for this modification.

2.1.5 Bally Sound Board Test Fixture

This test fixture is designed to test some Bally boards (-32, -50, -51, Cheap Squeak, and Squawk & Talk sound boards)

2.1.6 Bally 6803 Test Fixture

This is a complete test fixture with switch and lamp matrices and is able to test the 6803 MPU, displays, and sound boards found in Bally 6803 games.

2.1.7 Stern SAM II Test Fixture

This is a complete test fixture with switch and lamp matrices, which can test Stern MPU-100 MPUs, lamp boards, solenoid driver boards, SB-100 sound boards, and 6-digit displays. It can also test comparable Bally lamp boards, solenoid driver boards, and 6-digit displays.

SAM II Test Fixture Manual

2.1.8 Stern SAM III Test Fixture

This is very similar to the SAM II fixture, and SAM II test fixtures are often relabeled as SAM III test fixtures.

Stern SAM III ROMs (Note: currently untested in a test fixture)

2.1.9 Stern SAM IV Test Fixture

This is a complete test fixture with switch and lamp matrices, which can test Stern MPU-100/MPU-200 MPUs, lamp boards, solenoid driver boards, SB-100/SB-300 sound boards, and 6-digit/7-digit displays. It can also test comparable Bally lamp boards, solenoid driver boards, and 6-digit/7-digit displays. It can also be modified to test some Bally sound boards.

Stern SAM IV ROMs (Note: currently untested in a test fixture)
Stern SAM IV test fixture photos (elkhartpinball.com)

2.2 Gottlieb

2.2.1 System 1 Test Fixture

There were possibly 2 or 3 versions of System 1 Test fixtures, plus a stand-alone "playboard simulator" test box.

The earliest test fixture version had a flat surface for the circuit boards, and a vertical backboard surface for the displays, test buttons, and indicator lamps. Later version(s) of the test fixture were build as a large portable case with a flat surface for all the circuit boards, displays, test buttons, and indicator lamps. It also had a cover for the fixture, and two legs to tilt the fixture at an angle while on a workbench.

The playboard simulator was intended to simulate all the switches, lamps, and coils of a playfield, cabinet, and coin door, which could be connected to a boardset in an existing game or custom fixture. This was a portable box with a grid of buttons and lamps for diagnostics.

2.2.2 System 80 Test Fixture

There were at least two versions of system 80 test fixtures. The earlier test fixture was designed for system 80 & 80A games, while a later test fixture was designed for 80, 80A, and 80B games.

An official modification kit released by Gottlieb was released to upgrade test fixtures in order to be able to test sound/speech boards. The kit included an MA-188 sound & speech power supply, a small wiring harness, A small interconnect harness, a large capacitor, two toggle switches, some hardware, some labels, and installation instructions.

There are at least two booklets of official documentation for the system 80 test fixture. The earliest booklet was just a typewritten packet titled "D. Gottlieb & Co. System 80 Bench Test Fixture", and a later bound booklet (like the official parts catalogs) titled "System 80/80A Bench Test Fixture Operational Procedures".

The test fixtures are operated by a system 80 MPU inside the fixture with special test ROMs installed in it.

2.2.3 System 3 Test Fixture

The Gottlieb System 3 test fixture is unique in that it is the only vintage test fixture that was operated by a desktop computer (which includes Intel Pentium, Intel Pentium Pro, and Intel Pentium II eras).

The fixture itself is a portable box with a lamp matrix, speaker, and various system 3 connectors. It carried the official name "Gottlieb P.C. Board Tester".

The fixture came with various wiring harnesses in order to connect the various system 3 boards and displays for testing. There is also a smaller white box, which appears to be equivalent to the metal power box in a system 3 game.

The test box was driven by an ISA-based I/O card installed in the computer: a Contec PIO-96W(PC). Datasheet, Archived product page, Manual

Drivers:

The test fixture was operated by an MS-DOS program with the short name of "PINTEST". The latest known version is 1.21. It can run in MS-DOS natively or within (at least) Windows 98. The software displayed numbered lists of tests that could be run using the software and test fixture, and instructions on what steps were required to prepare for testing specific boards.

The MPU, DMD controller board, and sound boards required special test ROMs to be installed prior to running tests.

A video of a driver board test can be seen on facebook.

2.3 Stern/Data East/Sega

2.4 Williams

WPC-89/WPC-S/WPC-95 Test fixture ROM files (planetarypinball.com)

2.4.1 System 3-6 Test Fixture

The System 3-6 test fixture can test the MPU, driver board, sound boards, power supply, and displays. It can also be modified to accommodate 7-digit displays, System 7 MPUs and sound boards, and hyperball boards.

Williams System 3-7 test fixture manual

2.4.2 System 9-11 Test fixture

The System 9-11 Test fixture can test boards found in System 9-11 games. A common modification is to swap out the P1 and P2 digit displays for alphanumeric displays in order to test System 11 boards.

Williams System 11 Test Fixture Manual (16-2013T-101)
Williams System 11 Test Fixture ROM for U27 (ST11TS256.BIN) Note: This file is not available at Planetary's test ROM page, hence it being offered here.

2.4.3 WPC-89 Test Fixture

This test fixture was officially named the "Field Tester" or "WPC Field Tester". There are two main variants of the WPC-89 test fixture. The early variant was designed to test WPC-89 boards with alphanumeric displays. The later WPC-89/WPC-S test fixture was designed to test DMD boards. An add-on module was available to loead test fliptronic boards, named the "fliptronic test board assembly", part number A-15876.

This test fixture does not have a complete lamp and switch matrix.

Sometimes factory test fixtures differed from that of the text fixtures that were produced for operators/technicians. For example, this original WPC-89 & WPC-S factory test fixture was only intended for use inside the Williams pinball factory for testing/diagnosing assembled playfields.

2.4.4 WPC-95 Test Fixture

This test fixture was officially named the "WPC 95 Field Test". The WPC-95 Test fixture can test WPC-95 boards. It has a complete switch and lamp matrix, an improvement over the WPC-89 test fixture.

A video of this text fixture in operation can be found here.

2.5 Alvin G

2.6 Atari

(archived link for nuatari.com)

2.7 Capcom

2.8 GamePlan

The GamePlan test fixture was enclosed in a large brown box that could be folded and latched closed. It contained a full set of boards, displays, speakers, lamp matrix, and switch matrix.

2.9 Zaccaria

3 Diagnostic Tools

3.1 Universal/General

3.2 Bally/Stern (Classic)

3.3 Gottlieb

3.3.1 System 1

3.3.2 System 80

3.4 Stern/Data East/Sega

Switch matrix tester, lamp matrix tester, special solenoid input/output testers (siegecraft.us)

3.5 Williams

3.5.1 System 3-11

3.5.2 WPC

Switch matrix tester, lamp matrix tester, Flipper opto board tester (siegecraft.us)

3.6 Alvin G

3.7 Atari

3.8 Capcom

3.9 GamePlan

3.10 Zaccaria

Switch, lamp, and solenoid testers (pinballsolutions.eu)

4 Custom/Homebrew/Bench Test Fixtures

Various examples of test fixtures (pinside.com)

4.1 Bally/Stern (Classic)

Photo of Baby Pacman test fixture (pinrepair.com)

4.2 Gottlieb

System 1/80/3 test fixture solutions & ideas (flipprojets.fr). Located under The Projects > Materials, The Projects > Displays, and The Projects > Various > Built by our Readers

4.3 Stern/Data East/Sega

4.4 Williams

4.5 Alvin G

4.6 Atari

4.7 Capcom

4.8 GamePlan

4.9 Hankin

Hankin custom test fixture (aussiearcade.com by Skybeaux)

4.10 Zaccaria

Pinball Test Fixtures