Today’s I’m looking at a 1978 Bally “Supersonic” pinball machine. A friend had this in storage for a long time. While the game was in pretty good shape for its age, the original MPU board still had the battery on it, and the electrolyte from it leaked all over and damaged many components. Here’s a first look at the game.
This is another one of those video series where I thought to myself, “If I were smart I would edit this.” But then I thought, I can’t be the ultimate pinball repair guru and I’m not really trying. If I have some kind of “angle” it’s that I’m doing a FPS (First-Person-Shooter) perspective to the hobby, collecting and restoring. And often times when you’re in an FPS, you poke your head down the wrong hall and get fragged. This is kind of how this video series starts off but it takes part 3 to realize the plot twist…
Ok I’ll get off confusing metaphors and back to pinball repair..
The problem I had was when I got this Bally Mystic, one of the targets was broken. I had ordered replacement targets. I opted for the same style as the side targets even though on many Bally Mystics, for some reason, the front targets are bullseyes and the side targets have explosion graphics on them. Go figure? Anyway, after replacing the targets I discovered that two of them would often get stuck in the “up” position and would often not retract when hit. I knew the springs on some of the targets were old and had “lost their zest” (that’s an official technical term by the way). So I thought I’d make a video on replacing the springs, showing an alternate source for some of the components as well as a trick to make an old spring kinda new. Along the way I discovered the real reason why the drop targets weren’t resetting…
In taking an initial look at the latest game I picked up, this Bally “Mystic”, as always my main concern is checking to make sure there’s no significant battery damage on the game. What’s interesting is when I looked at the game, there was no battery on the MPU board. The owners insisted the game saved the high scores, but I didn’t see how? Was there a battery on the underside of the board? I had to pull the MPU out to see.
What I saw was a board that someone had repaired, that had leaking batteries on it. They simply pulled the board and replaced a few damaged components and did not put a battery back in. But they created another issue by not fully-cleaning the board, and as a result, the damage from the leaking battery, even though it was long gone, continued…
The other day I was reminded of how important it is to make sure you fully mitigate battery acid leakage on circuit boards. A friend picked up a STTNG (Star Trek the Next Generation) pinball machine. I’ve been systematically going over the game trying to get it working. When I first looked at the backbox I noticed wires had been run for a remote battery pack – I thought “good deal, one less thing I have to worry about.. the MPU board is clean…” so I went about working on other areas of the game, checking switches and optos and everything. After I got the game booting up I discovered the start button would not work. After spending a bunch of time testing all the wires and connectors and still not finding the culprit I took a closer look at the MPU board where the cabinet switches plug in… 
I have seen acid damage before, but nothing as sneaky and widely-spread as this. Components all across the main processing board were showing signs of corrosion and damage, but I could also see that repairs had been done, several components and ICs had been replaced and sockets added. Someone cleaned up battery damage and added an external battery pack. But there was still major corrosion on the board… what gives??
My theory is that whoever cleaned the circuit board, instead of using vinegar and multiple paper towels or q-tips, they probably used a single wipe, and in the process of cleaning the circuit board, actually spread the acid all over the components! At the time, they thought it was clean, but they actually made the problem worse.
This is why it’s very important to thoroughly clean off any leaked electrolyte from batteries, and use vinegar to neutralize it, and use multiple wipes — do not wipe from one area to another area. Work on small parts of the board at a time, throw the q-tip or paper towel away and use a clean one when you start to work on another area of the board. Do not risk spreading the acid to previously un-damaged components.
(in no particular order of importance)
One of the most common “gotchas” when working on pinball machines is the tendency to pick up the playfield while the game is powered on. Most of the time this can be harmless, but there’s always that off-chance that a wire or solder joint can brush against a siderail, or a screw, nut or other playfield piece comes loose and shorts an electrical connection. if you need to pull the playfield up, power down the machine, lift the playfield, then turn the power on.
Some enthusiasts new to pinball repair often try to clean or work on the entire machine when addressing one specific issue. The unfortunate end result can be one-step-forward, three-steps-back. This is especially true with EM games. If you find one switch that may need adjustment or cleaning, resist the impulse, while you’re there, to go through and clean them all. Until you become very familiar with a game’s architecture, it’s best to not poke around in areas that appear to be working properly.
Spend the money and take the time to use proper tools and techniques when working on games. From crimping and riveting to files and types of sandpaper, paints and soldering/desoldering tools, don’t skimp. Good quality tools will save you time and money. Cheap tools will give you headaches and cause damage. Invest in a reliable jack to raise and move your games. Have a comfortable, well-lit work area. Have parts well-organized and easy to find. Have plenty of spare storage bins and a system to label and store parts on works in progress.
Take lots of pictures, before, during and after your work. If you unplug connectors or disassemble parts, take pictures of the way they were before from multiple angles. I like to keep a little book with each game that chronicles what I’ve done to the machine and its history. I will also stick a post-it note on the top glass where I can make notes on items that need work with each game. This way when it comes time to perform maintenance on problem X, I’ll also note that while I have the machine apart, I should fix items A, B and C that are on my little post-it note. It’s frustrating to pull a game apart to fix a sluggish flipper, put it back together and then realize there are a few lights out I should have replaced at the time.
For solid-state machines, if you are lucky enough to have a vintage machine with no acid damage from batteries, don’t take any further chances. Install a remote battery pack, memory capacitor or other solution which will eliminate the problem. Change your batteries in the machine once-a-year just to be safe. Many of us also believe not all battery brands are equal. (I will not put Engergizers in my machines)
The #1 cause of damage to playfields is the result of aging pinballs that start to get scuffed or corroded and end up acting like sandpaper, tearing up playfield art, mylar, clear coat and everything else in their way. Balls are cheap. Regularly replace them if they begin to look even the slightest-bit rough. Also make a point of routinely dusting/cleaning the playfield. Swiffers work very well for getting into tight places and removing grit that could cause wear or balls to get stuck. Waxing (with 100% Carnuba wax) is always a good thing to do too, but be careful about getting wax residue in places you can’t clean it away.
A 14th century philosopher, William of Ockham is credited with the maxim, “Occam’s Razor” which states, “Simpler explanations are, other things being equal, generally better than more complex ones.” Don’t make an issue more complicated than it needs to be. If your machine suddenly says 7 different playfield switches are no longer working, don’t assume you have 7 different switches broken; instead perhaps there is a common wire that has failed which is affecting all 7 switches? Look around for anything unusual and if you see something odd, use your eyes and experience to deduce where it needs to be.
Usually when things go wrong, beginners will get bogged down in seemingly more-direct “solutions” when the problem is the result of something even more simple than they imagine: a flipper not working? Beginners might start replacing coils and rebuilding things before checking to see if a fuse is blown, wire broke off or a connector isn’t plugged in all the way. You can often save time by pursuing the most common/easiest-to-fix cause of an issue, as opposed to the most obvious potential failure point. Along these lines, it’s safe to first check things like: fuses (noting that on most games there are fuses all over the place, even under the playfield itself – don’t assume a fuse is OK unless you physically remove it and check it), connectors (loose connectors or bad pins on connectors are a major cause of most problems), bad grounding (again, loose wires or boards not properly screwed into a grounding backplane).
Any time you’ve transported or picked up a new game, resist the urge to quickly plug it in. Even if it was working 100% before you put it in your vehicle, transporting a game can cause things to shake loose, especially connectors, and you don’t want to run the risk of damaging the machine. Before turning the game on, go through the entire machine and make sure all the connectors are properly seated and nothing looks out of place. If you turn a game on and a high power coil is locked on, power it down before the coil burns out.
A lot of times games are damaged or even destroyed as a result of people not knowing how to pack and move a game. NEVER transport a game with head upright (for modern games the head can be folded down; older games the head should be unplugged and detached from the cabinet). If you don’t have 2+ people to move a game, do not try to do it yourself, or break the game down and move it in parts. It may be a pain to pull the playfield out and detach/re-attach things, but it’s much better than screwing up your back or damaging parts trying to move everything all at once.
Also be aware that there are many fragile parts to these games. Be extra careful with any tempered glass and backglasses. They can easily get scratched. Tempered glass, while designed to be impact resistant, is also very sensitive to “exploding” if damage is caused along the edges, or is exposed to rapid temperature changes. Also remember that moisture is a killer! Some backglass artwork can instantly delaminate if gotten wet. Some cabinets are made out of medium-density-fiberboard and will puff up and start to disintegrate if exposed to water. Extra care needs to be taken. When moving machines, always tighten down the cabinet, BUT NOT TOO TIGHT or you can break glass or ding the head and siderails. Always remove the balls from the machine and any other parts (or coins) inside the cabinet that could bounce around in transit.
The best way to find out what’s wrong with a pinball machine is use your eyes. Examine the game in detail and look for anything out of the ordinary. Even if it seems unrelated to a problem you’re having, like a light not going on or a switch not registering, and you find some odd, loose wire at the other end of the playfield, there’s a good chance they’re related.
As many of you know, one of the biggest problems with pinball machines and repairing them is dealing with leaky batteries on solid state machines, that cause corrosion and all sorts of damage. I’m going to go over how you can completely eliminate this from happening by replacing old-style rechargeable batteries with a high-tech “memory capacitor” that will last longer and not have the same problems that batteries do.
Now lets test the new memory capacitor in the game:
Here’s source info on the caps:
Category:
1.5f 5.5f “super capacitors” at Mouser Electronics.
Specific item I used:
You can also get these from Great Plains:
http://www.greatplainselectronics.com/Category-67.asp
Product ID: CER-1.5F-5V
Capacitor, Radial Electroltyic, 1.5F, 5V
Capacitor, 1.5F, 5V, 85C, Radial Electrolytic
Manufacturer: Panasonic
Manufacturer Part Number: EECF5R5U155
Diameter: 21.5mm, Height: 8mm, Lead Spacing: 5
Price: $5
In this latest episode I deal with a sound problem on our Mr & Mrs Pac Man pinball machine. The sound and speech is intermittent and low in volume.
When dealing with any game that is 30 or more years old, you can bet that the capacitors are suspect. These electronic components are known to go bad over time, since they have liquid inside that can dry up, or leak out. It’s relatively easy to acquire and replace the components provided you have the right tools, and then you insure your game board will ideally last another 30 years.
In the video one thing to note is you aren’t always limited to having to find the exact same value/model capacitor. You can replace a capacitor with a lower voltage rating with one of a higher voltage rating. (i.e. replace a 25v cap with a 50v) But you want to make sure the capacitance value (in farads or microfarads) remains the same. You can also replace an axial cap (one with the leads coming out of each end) with a radial cap (with both leads coming out from just one end) as long as you get the polarity properly oriented. Make sure you note that markings usually point to the negative lead, while an indentation on one side of a capacitor will mark the positive lead.
After replacing the caps, we still have some flakyness with the speech portion of the board. I’ve got some replacement pots on order – when they come in I will check on the board traces and solder joints and probably replace that pot… stay tuned and thanks for following the saga!