An odd assortment of things are wrong on this TSPP pinball machine. Are they related? Let’s look into what’s wrong and where we should look to fix things?
This has now turned into a multi-part series where I also discover some other issues:
So here’s the take-away from the first 5 parts of this series.
Everything was basically inter-related (except I believe the slingshot and pop bumper coils were separate failures). The trouble with the ball trough opto led to the failure of the shooter lane coil. When the ball trough opto started failing, it signaled false switch closings, tricking the game into thinking balls were moving through the trough and causing the VUK to try to clear a problem, which caused multiple balls to go into the shooter lane. This happened faster than the auto-plunger could handle and once X number of balls went in there, the plunger could not clear them, and eventually the MPU sent too many “fire-the-coil” signals and blew the driver transistor — interesting that it blew the driver transistor before it melted the coil — I suspect either (or both) can happen in this circumstance.
What’s interesting about this, is that this problem could be compensated for by software. It’s also possible the other coil failures are the result of a similar characteristic: Not having a certain timeout or duty-cycle enforced on coils. Meaning… the software could check to make sure that if a coil is firing too much (say x amount of times in y time), that it knows there’s some kind or problem and then put the game into some sort of error state rather than blow the coil or the drivers. I know in some later games this happens… when errors are encountered, the game just stops trying to fire coils rather than blow them.
This obviously isn’t the case in some of these 2000-era Stern games. I’ve noticed this on several titles including WPT and NBA as well.
Unfortunately, there’s not likely to be a software fix available, so what is important is to keep an eye on game behavior and try to catch switch malfunctions before they blow things. Had I been told about the shooter lane situation earlier, I could have fixed the opto before it blew the driver transistor on the SDB.
After having this game on location for awhile, I thought I might report on what types of wear and tear and damage I’m running into, and what was wrong with the game. I think we’ve found a few “weak links” relating to parts that probably should last a little longer. Check it out:
This is a very cool game that is surprisingly rare. A 2008 Stern “NBA”. Rumor has it the game had a very low production and was mainly made for the Chinese market.
I had a chance to get one of these games that had been stuffed in the back of an operators office for many years. It needed quite a bit of work. Here is the whole video series from first look, to the repairs, to the showcase of gameplay:
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/
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/
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).
In this 2-part series I go over installing a shaker motor in a Stern Jurassic Park pinball machine. I also run into a few weird glitches with the hardware sent me. That’s the world of pinball… nothing ever goes 100% smoothly does it?