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:

Sound and Speech board ground mod tap
Sound and Speech board ground mod tap
Alternate ground mod location for sys80 CPU board
Alternate ground mod location for sys80 CPU board

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.

Rebuilding/Bulletproofing Gottlieb Pop Bumper Driver Boards

This is a series of three videos covering before, during and after, demonstrating problems with Gottlieb System 80 pop bumper driver boards. There are some basic things you want to do to make them work better and more reliably.

Summary of Pop bumper board mods:

  • First, check to see if you have older, or revised boards and convert older versions to the new revised version
  • Replace 47uf cap with 100-200uf cap
  • Add a 4.7uf 10v cap on underside to help with “phantom pops”
  • Re-flow pin headers and make sure to remove any oxidation from the pins
  • Test the driver and replace with a Tip102 if needed
  • To reduce “ghost pops” you can add a 47uf (10v-16v) cap between the pins displayed below:
Location of optional 47uf cap
Location of optional 47uf cap

Pinball Showcase: 1969 Gottlieb “Target Pool”

This is a very fun game that I recently dragged back to my house to work on. It was being a bit cranky and I finally got a chance to fiddle with it and get it working. I’m still tweaking it but wanted to do some gameplay videos. I forgot how really fun this game is. It’s all about nudging. This is one of the best games to learn the subtle art of nudgng on and widely regarded in pinball collection circles. Come see what the fuss is about..

Pinball Showcase: 1967 Gottlieb Hi-Score

This is a game I featured in episode #17 of pinball stories. A recent game I picked up and was sitting in my living room that I’ve been working on restoring. I finally got the game playable and wanted to do a test-stream of my camera rig so why not do a Pinball Showcase? What you have here is a portion of the live stream of me demo’ing the 1967 Gottlieb Hi-Score pinball machine. A surprisingly fun game to play, albeit a rather simple and shallow rule set.

In the video I explain the rule set but I wasn’t immediately able to figure out under what conditions the reward scale for the roulette wheel resets. After playing a few more times I figured it out. If you hit the max payout for A, B or C, it then resets, otherwise it will remember and carry over the current payoff scale from ball to ball AND player-to-player. So this means it’s possible for a player to steal the progress of another player for a larger roulette payout. That’s pretty cutthroat!

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