(Added a poll for fun)

I have seen two general schools of thought when it comes to restoring, or maybe a better term is renewing, an EM machine to get it playable.

One says don’t mess around with things, just fix what needs fixing and move on.

The other days, tear everything down and renew/rebuild it all.

I see good reasons for both methods. The first method will get you going quicker and reduce the chances of you yourself creating more problems due to dinking around with things. The second method gives a better chance of fixing all the problems, but it takes more time and effort and and it is best if you really know what you are doing.

I got a Bally Monte Carlo (1973) a few years back, the price was very good and the condition was so-so, but I knew that and it was fine with me because I was interested in learning how to fix it.

When I got it and looked at it, it was a filthy mess. It looked like it might have even been left outside for a while, or in some sort of poorly sealed shed maybe. I cleaned up as much loose stuff as I could, then I decided to take the first approach of just fixing things as needed. Several years later, I finally got everything working as it should, well almost, I still can’t get the tilt trip relay to work, but I’m going to leave that for now.

When I started, I immediately found out that besides being dirty, the machine had been pretty well mistreated. The first things I found were related to bad hacks like terribly bent switch blades, and weird stuff like a loose screw jammed into a mechanism. It was almost as if it had been deliberately sabotaged. Relay connecting wires for the gates fallen off. The credit wheel was screwed on 180 degrees off. All sorts of stuff like that.

I methodically went through and fixed things and got each thing working. The machine became basically playable but there were things here and there that didn’t work quite as they should which bugged me of course. I went through the schematic until I understood every piece and then used all the troubleshooting I could think of, but problems persisted. As an example, the mushroom bumpers would open their gates as they should, but they wouldn’t score 100 as they were supposed to. I figured out with jumpers that everything was working as it should and that it must be a wiring problem. But I couldn’t figure out where the wire problem was.

Sometimes as I was trying something to troubleshoot a problem another problem would randomly pop up that didn’t seem connected to what I was doing, but must have had something to do with me messing around. Then I would have to troubleshoot that. Finally, one day on a whim, I unplugged and replugged the Jones connectors between the backbox and the cabinet. Lo and behold, the mushroom bumper problem was solved! It must have been due to one connector not making a good connection due to dirt or corrosion. I still had some playfield lights that were acting weird. I took some of the connectors off and cleaned them a bit and then plugged them in, then it started blowing fuses for no apparent reason. Then I unplugged and replugged it in and it seemed ok. I got the reset relay bank up and out and cleaned everything and checked the action of all the relays. Then all of a sudden one of the weird lighting issues that I had for years was gone! The problem is, I don’t know what I did to make it go away, which I don’t like.

As of now, everything is playing as it should. But I’m afraid to mess with it too much. I’m going to finish it up with pop bumper and flipper rebuilds, then just set it up to play.

After going through this, I would have to say that in the case where you get a dirty and jacked up machine it might be better to completely tear everything down, clean it, and reassemble it and tweak it. The reason is because of the filth and corrosion everywhere combined with previous people hacking on it. Potential problems can be hiding everywhere, and weird intermittent problems will haunt you. As I found, even a single connector on a Jones plug that is slightly corroded can cause strange problems. This way you could be sure that everything is cleaned and optimized. I probably will even do this someday with this Monte Carlo, if I have more time and space to do it. I would pull the playfield off, completely disassemble it and clean everything, pull out the relay board and disassemble and clean it all, pull out all of the Jones connectors and clean them and buff them, check all of the switches, rebuild all the steppers, etc.

While it’s all apart, might as well then give a shot at restoring the playfield, which isn’t horrible but could definitely benefit from a restore.

This would be a fun project, assuming you enjoy that kind of stuff, and the end result would be a nice machine that will last many more years. Problem is, it’s a Monte Carlo, and while it is a pretty good looker it’s not a very popular or valuable machine. Even fully restored and nice it’s probably worth barely $1000. I kind of like it though, it’s pretty fun to play and it’s hard as heck to get high scores. Plus Dave Christensen art never gets old.