Products >> Pinball Diagnostic Tools >> Bally/Stern Solenoid Driver Board Tester

Bally/Stern Solenoid Driver Board Tester

These are a set of testing tools for Classic Bally/Stern pinball machines (ie. machines with Bally-17, Bally-35, Stern MPU-100, Stern MPU-200 MPUs in them) for testing solenoid circuitry on the Solenoid Driver Board.

There are two boards..

The 1st board is the "Output Tester" and has a bargraph led on it and connectors that can attach to headers J1, J2, J5 on the SDB. No harnesses are needed, but you do need to connect +5v to the tester board.

The 2nd board is the "Driver Tester" portion. It connects to J4 on the Solenoid Driver Board (the solenoid data inputs & solenoid select line). You need to connect +5v and GND to this board.

Please note that on Stern SDB's if the original oversized high voltage capacitor is still there, there may be a clearance issue at the J1 header when using the "Output Tester" board for testing Q4. Normally these capacitors should be replaced anyway when servicing the board due to age. Newer capacitors are much smaller and will not have a clearance issue. This only affects Stern SDB's with their original oversized high voltage capacitor on them.

"Output Tester" Features

  • Identify locked on transistors
  • Use during the MPU self-test to see solenoids lines activate properly
  • Has all 3x SDB output headers (J1, J2, J5) on a single board!
  • No big harnesses required, just plug in and connect +5v to the header

"Driver Tester" Features

  • Simulate solenoid signals to solenoid inputs at J4 on the SDB for FULL TESTING
  • Use during the MPU self-test to watch solenoid data lines are pulsing
  • Simulate both momentary & continuous solenoids
  • Use in-game or at the bench
  • Easy solenoid reference chart (for DIP switch settings) printed on the PCB
  • No big harnesses required, just plug in and connect +5v/GND to the headers


One big advantage is the ability to easily test SDB "stand-alone" (ie. not connected to any other boards, just using the testers & connecting GND/+5v to everything including the SDB test points). With both tester boards connected you can simulate the solenoid signals with the "driver" tester (ie. select via DIP switch the solenoid to activate, press the momentary button to activate). This should then light up the corresponding led of the transistor being activated on the bar graph led of the "output" tester. Very useful to anyone going through a lot of SDB's that wants a quick way to verify transistors before putting the board(s) back into a machine. You just reference the silkscreen chart of the solenoid you'd like to activate

In the picture below (right) Q14 was selected. The chart shows "0110" (so off-on-on-off on the DIP switches). DIP switches are set & the momentary button is pressed to light up Q14. If it doesn't light, you can use a logic probe along with the driver tester to isolate exactly where the issue is occurring.



There's a bunch of options for in-machine testing. With both boards connected you can do everything like you can at the bench (ie. manually trigger solenoids) but you can also watch solenoid signals being sent by the MPU too when you piggy-back the wire harness at J4 onto the "driver tester" header. The bar led's above the DIP switch will light up and correspond to the solenoid being selected. This is very helpful to identify missing signals by a quick visual check of the leds. If you have an issue where the wrong solenoids are being activated, it's a great way to isolate which signal is missing (ie. one of the bar leds above the dip switches never lights up during solenoid test) and you can isolate which wire/pin or signal on the MPU needs to be looked at to further diagnose and fix the issue. You can of course also watch the outputs on the bargraph led to identify locked-on or non-working transistors -- or if the bargraph led lights up for a solenoid that isn't working at all, then it would help identify a board versus wiring / mechanical / missing signal issue.

Youtube Demonstration Videos (in-machine testing):

Video #1 - In-Game Testing (watching solenoid signals on the driver)
What's neat here is the leds lighting up above the DIP switch will correspond to the chart silkscreened on the board. In other words "1001" would be DIP switch setting "on-off-off-on" and the leds above the DIP switch would be "lit, not lit, not lit, lit".

Video #2 - MPU Self-Test (watching both the solenoid signals on the driver & the outputs on the bar graph led tester)
Here both boards are being used while the MPU is cycling through solenoids in self-test mode. You can see the signals coming into the SDB to select the solenoid and also see the outputs are lighting up the solenoid being pulsed.

Video #3 - Manual Driving Solenoids (setting DIP switches & manually activating)
Here I manually drive the solenoids while the board is connected in the game. Of course you can also fire solenoids by grounding transistor tabs.. but this doesn't tell you that the circuitry on the SDB is working -- just that the transistor is functional.


These testers can be purchased individually or as a pair. They work best as as a pair since you can both drive the signals to the SDB (with the "Driver Tester") and view that the solenoids are activating easily with the "Output Tester".


Bundle #1 - Bally/Stern "Output Tester" & "Driver Tester"
Get the pair of testers and save a few bucks. You get 1x Bally/Stern SDB "Output Tester" and 1x Bally/Stern SDB "Driver Tester".

$49.95ea (Fully Assembled) $32.95ea (Kits)

At this time if you are interested in purchasing this item, please CONTACT US via email.

Bundle #2 - 3x Bally/Stern "Output Tester" & 1x Bally/Stern "Driver Tester"
This bundle is for people that want to connect to all 3x output headers on the SDB at once. You get 3x of the Bally/Stern SDB "Output Tester" and 1x Bally/Stern SDB "Driver Tester".

$86.95ea (Fully Assembled)
$56.95ea (Kits)

At this time if you are interested in purchasing this item, please CONTACT US via email.

You can also purchase these testers individually if you would like. While these testers work best as a pair, they can also be used individually to some degree. If you already have other test equipment that serves the purpose of one of the testers then you can just purchase one or the other.

Bally/Stern SDB "Output Tester" ONLY
$23.95ea (Fully Assembled)
$15.95ea (Kit)

At this time if you are interested in purchasing this item, please CONTACT US via email.

Bally/Stern SDB "Driver Tester" ONLY
$29.95ea (Fully Assembled)
$18.95ea (Kit)

At this time if you are interested in purchasing this item, please CONTACT US via email.

  This item ships only to United States, Canada & Australia


Items are shipped from the United States. ASSEMBLED "Pinitech" PCBs are manufactured in the US and are currenty only shipping to the United States, Canada & Australia. DIY Kits and Bare Boards may be available to other international customers. See below for details.

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As of March 2017, there is now a $25.00 minimum order (excluding shipping fees) for international orders due to postage costs. You may still submit an order via the shopping cart at this time, but please note that some orders may not be accepted if they don't meet the minimum order amount. This may change in the future to orders via email only.

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