Recommended Gottlieb System 80 Ground Mods (Haunted House – Part 9)

Now that I’ve got Haunted House running, it’s time to bulletproof the game – ideally you’d probably want to do the ground mods from the very beginning because in some cases, you might not be able to get the game working otherwise, but in this case, I managed to get the game to boot and appear to play well, so now we’re doing the required ground modifications to make the game more stable and reliable.

What’s actually involved in that?

It’s pretty simple. Gottlieb used single-sided edge connectors (unlike Trifucon which has contacts on multiple sides) for most of their connections. Over time, these connectors tended to fail, either by the contact surface becoming oxidized, or the blades becoming fatigued and not making good contact. Since ground is so important, without a solid contact, the game can behave in a variety of different and unpredictable ways, from random reboots, to intermittent issues with everything from lights to sound to coil firing. The general rule with Gottlieb games is if you’re having a weird problem that isn’t consistently repeatable, there’s a good chance it’s related to the powertrain. The most obvious culprit in the power chain is going to be the ground/return lines.

In-a-nutshell, the ground mods involve running an extra ground wire to tie all the different board’s ground lines to a common ground, and tie the head and the cabinet ground lines together — the only exception is you keep the 45v solenoid ground line separate (this is to ensure that if there’s a coil short, it doesn’t send high voltage to the rest of the game’s more sensitive components). Each board has a different recommended spot where you should tap into the ground, often it’s near one leg of a capacitor (which should also be changed if they’re original). Use 18 gauge wire (preferably green colored) and tap into each board with one end in the designated spot, then crimp a spade terminal on the other end and tie all the boards to a single ground plane (usually the metal bracket that mounts the power supply in the upper left corner — be sure to sand the paint off the area so you can make contact (alternatively you can also solder directly to the bracket.

Once you have all the boards tied to a single plane, you want to tie that to the head and the cabinet, by running wires from the power supply bracket to the metal frame in the head, and then one down into the cabinet to the transformer board, where you’ll find a ground backplane you solder to (on System 80B games, you’ll also want to take all the ground wires that terminate on the transformer board and tie them together, preferably eliminating the molex connectors they used which cause problems).

Click at the top of each image below for larger versions:

Haunted House Lives! (Parts 4-7)

This is part of the ongoing series of restoring a 1982 Gottlieb “Haunted House” pinball. From crazy wiring problems to system upgrades, I’m taking you along with me on this scary ride.

In this next series, I tackle one of the most intimidating problems: a huge mess of hacked wiring. Can we untangle this mess? Will the game actually work? Let’s find out!

You can see the previous parts here.

Stuck Flippers? Sometimes the problem is not what you expect..

Anybody messing with pinball machines will undoubtedly encounter problems with flippers. Often they seem to get “stuck”, will stay up and not go back down or behave weird. We often instantly go to the flipper mechanism to look for a problem, but sometimes it’s not there.

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BSOS Custom Paragon Pinball Update – New Modes!

Here is an update to my progress completely re-coding a 1979 Bally Paragon pinball machine, with an Arduino Nano, with all new rules and operating system. This game will be an enhanced version of the original with extra features and deeper modes, and 14-channel polyphonic CD-quality sound.

For more visit: https://pinballhelp.com/

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Building a custom micro-controller for early Bally/Stern solid state pinball machines

This is an introduction to an up-and-coming technology that a small group of pinball and electronics enthusiasts are developing. A custom microcontroller that interfaces with Bally-35 MPUs and allows you to write customized rulesets, even completely re-theming games. This is the first part of a journey that I hope to take everybody on.

NOTE: This is a video I recorded several months ago that I forgot to make public, so I’m much further along.. But thought it might be interesting to show this early look at the development of this technology. Now there are etched boards that can be acquired.

What’s involved in programming a pinball machine?

After restoring a vintage 1979 Bally Paragon Pinball, I go on a quest to see what’s involved in re-programming a game like this and doing my own, custom ruleset. You may be surprised at how many things you have to take into account and keep track of. Let me show you some early progress trying to hack a pinball and re-design a new operating system and set of code.

This video goes over some general, philosophical considerations in pinball design. In future videos I will dive in deeper into the specific technology and coding.

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