How to properly clean battery damage off a MPU board

This is the next video in my series of work on Paragon. After the first look (http://pinballhelp.com/first-look-bally-paragon-pinball/) I discovered there were still issues with the MPU board that were the result of continued corrosion even after the battery was removed and the board was supposedly cleaned. Whoever did the previous work didn’t clean the board enough and corrosion continued. I’m going to do my best to salvage the board.

Quick demo of fully-modded Stern “Trident” pinball with new rules and sound

After getting my Trident operational, I installed the BSOS system and have been working on fine-tuning the custom code and sounds. Here’s a short demo of what the new Arduino-based controller does to a standard Bally 18/35/Stern early solid state game.

Resources (courtesy Dick Hamill):

The code is all available on GitHub. It’s broken down into a base library and then machine-specific implementations. Rewriting other games requires a moderate knowledge of C/C++.
https://github.com/BallySternOS

Here’s a suggested parts list. If you bought all these things, you could create 6 of these boards. If you don’t need that many boards, you might find cheaper ways to source smaller quantities. I haven’t done any work to figure out if this is the cheapest way to source any of this stuff.

Cheap Arduino knockoff x6 ($20.99) – needs CH340 driver for programming / has to be ATmega328P
https://www.amazon.com/ATmega328P-Controller-Module-CH340G-Arduino/dp/B08NJNJCTX/

0.1″ 40-pin connector (40 pieces for $7.99)
https://www.amazon.com/Honbay-Single-Female-Connector-Arduino/dp/B06Y4S6G29/

32-pin Prototype PCB (2 pack for $9.99) – this won’t work for Alltek or MPU-200 because they have a 34-pin connector
https://www.amazon.com/Prototype-Snappable-Arduino-Electronics-Gold-Plated/dp/B081QYPHHP/

Wire ($7.99) – tons of wire
https://www.amazon.com/REXQualis-Breadboard-Assorted-Prototyping-Circuits/dp/B081H2JQRV/

74125 – ($1.95) https://www.jameco.com/z/74125-Major-Brands-IC-74125-Quad-Tri-State-Bus-Buffer_49373.html

Boot switch – x2 ($8.99) this switch will work for activating the Arduino board and toggling the speaker (see the writeup here to find out why: https://ballysternos.github.io/install.html)
https://www.amazon.com/gp/product/B07XMH174C/

OR

@RoyGBev has created a PCB and kit (doesn’t include the Arduino) here:
https://pinside.com/pinball/market/shops/1304-roygbev-pinball/04736-arduino-nano-adapter-for-classic-bally-stern

How to make a test bench rig for Bally-18/35 MPU boards using a PC power supply

I found this old video the other day and realized I didn’t have a post on my main site showcasing this video so I wanted to add it (also, this was before I learned the proper pronunciation of “Bally” LOL…. bah-lee).

Fixing / Rebuilding Stuck Pinball Flippers on Early Ball/Stern Solid State Games

This is a short video going over the steps to repair/rebuilt/refurbish early solid state pinball flipper assemblies, such as those on Stern and Bally games (but this also basically applies to most pinball machines). I go over the process specifically on a Stern Trident and show the specific style of plunger and assembly they’re using, but most games use similar parts. You can use these techniques to rebuild/refurbish pinball flippers on most games.

Also, there’s another thing I don’t cover on the video that may also be a cause for stuck/sticky flippers, and that’s crud around the flipper button. Sometimes the flipper button assembly can be dirty and the button may stick – that can also cause the flippers to not behave properly, so be sure to check and clean the flipper button regularly too!

Rebuilding Drop Target Assemblies on Early Stern/Bally Solid State Games

Here is a series of three short videos covering the process of removing and refurbishing the drop target assembly on early Stern/Bally games. This is done on the Trident I’m working on restoring.

After unscrewing the switch stack and the reset coil, you can remove the drop target assembly from the game. Then you an remove the individual drop target coils from the assembly by unscrewing four small screws.
Note the inner plate behind the drop targets that has slid down – this is what the switch stacks screwed into, so you’ll want to connect them back to the assembly first, before putting the individual drop coil bank back in place.
Since I wasn’t replacing the targets, I simply soaked the assembly in hot soapy water, then made sure to dry it completely before applying some dry spray lubricant. I also shortened the springs by just a tiny amount to make them work better. If you have replacement targets, they should be removed and replaced, which is done by removing the retaining clip and axle holding the assembly together at the bottom.

Pinball game not starting? Switches not working? Here’s a trick that may work!

I’ve run into this problem at least 3-4 times in the last month with different early Bally/Stern solid state games: The game boots and appears to work but you can’t start a game and/or many switches/buttons don’t seem to work? Before you dive deep, try this simple, easy trick.

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which connectors on the Bally/Stern MPU board go to which areas of the game.

Prototyping A Brand New Mata Hari Ruleset!

I’ve been working on a new project that I’m very excited about. There’s been a movement to create an inexpensive, non-destructive and simple way to mod early Bally/Stern solid state games and add more features. In this video, I demonstrate an early prototype of the system used to modify a Bally Mata Hari pinball machine to include new features such as a skill shot, modes and even a wizard mode.

Want to learn more about this project? Visit: https://github.com/BallySternOS