This game pick up is a bit bittersweet. It reminds me of another game that slipped out of my hands and how different types of collectors in the community look at trading, buying and selling differently.
It’s a pretty heated argument among the pinball community whether or not there’s any true objective “ethics” involved in the buying and selling game? Everybody has their opinions, and I have mine, which is, I don’t step on other peoples’ deals. I honestly believe if you take care of others, you end up better off than if you play the dog-eat-dog, first-person-with-the-cash-steals-the-deal type strategy in pinball acquisition.
I’ve had this game sitting around for awhile and finally got around to looking at it. I shot a few videos awhile back and forgot to publish them, so here’s a useful short video on how to access the DMD in Slugfest. It’s nowhere near as easy as you’d expect as it is in a regular pinball machine.
I was going through some old videos that had been uploaded to YouTube that for some reason were not made public and found this one. It’s a short video on how to go through the diagnostics on these 80s era Bally pinball machines and track down switch matrix issues. I don’t go into how the matrix works in this particular video, but I do demonstrate how a stuck switch can cause odd behavior. In this case, the tilt triggers when a certain target is hit.
This is a game that’s been sitting in the back for awhile at my place that I keep meaning to get to, so I finally jumped back into to figure out what was wrong. It’s weird to go over notes you made 6+ months ago and try to pick back up where you left off — remind me not to do that.. LOL But the issue was relatively simple: The center bank of drop targets was not resetting.
In this series of videos, I go over, step-by-step the process of how to figure out what’s causing this problem, how to read schematics and manual diagrams, and the various points of failure, and once again, we are reminded of “Ockham’s Razor” which suggests the most obvious cause is the most likely… OR IS IT?
Interestingly enough, once I figured out where the problem was, rather than solve it the traditional way, I choose to do a “hack”… basically just to see if I could do it. The choice was, do you replace an entire 16-pin IC that’s only using one small part of it (involving adding a socket and a new chip that is pretty expensive and hard to find) or do you “hack” the damaged chip and piggyback a new component on top of it? Normally I don’t do these kinds of MacGuyver stuff on system boards, but it was a fun trick to try and it cost a few cents and about 10 minutes verses a lot more time than would have been used to replace a whole IC.
One reason why this hack job is particularly sloppy is because I had to work on the board in the game due to the previous owner having hard-soldered some wires to one of the connectors – that’ll be another future project to clean up all that mess, but for now, I needed to get this back working.
To understand what I did, here is a substitute circuit board showing the position of various individual 2N4401 transistors overlaid on the CA3081 IC package. Using this you can figure out where to insert a transistor manually on the IC pinouts if one of them fails: