Nine Ball Restoration Log – Part 1: Initial Assesment

30 November, 2008 (09:26) | Restoration Logs | By: admin

I picked up a Stern Nine Ball in the group of 5 Stern pinball machines that I picked up earlier this year. The friend who told me about the deal also got a Nine Ball machine in the deal. Later he realized that it was completely missing the large drop target bank and ended up trading it to me. The restoration of that machine will be covered in this restoration log. The machine is in amazing condition so I’m going to use the drop target bank from the Nine Ball machine I got originally and figure something out for that one later.

This has to be one of the cleanest machines I’ve ever restored. On the surface it looks like an easy restoration but there is a lot of rust in the mechanisms and the lamp sockets are almost all loose and only working intermittently. Both of those problems will be addressed but they’re the kind of problems that take a long time to fix properly. I’m also going to clear coat the playfield which will require me to disassemble most of the playfield. Between the lamp sockets, mechanisms and playfield prep this game is going to be in a million pieces for a while.

The MPU board was missing from the machine when I got it. Another friend had borrowed it from the friend that I got the game from so I’ll get it back eventually. In the mean time I’m using the MPU from my original Nine Ball machine. The lamp driver board is pretty crusty but mostly working. There are several lamps not working and a few stuck on so the lamp driver board will require some repair. The regulator/Driver board doesn’t appear to have any problems. The filter cap will be replaced but that’s about it for that board other than cleaning connectors.

The inside of the cabinet is immaculate. Definitely one of the cleanest games I’ve seen inside. The transformer has a major layer of rust on it though. It was definitely stored in a damp environment for a few years. Fortunately the rectifier board and connectors look pretty solid so I probably won’t do anything here until something breaks. Typically I would rebuild the rectifier board and replace the connectors but this one doesn’t really need it right now.

The next 2 pictures show the rust that is present throughout the machine on the steel parts. All of the effected mechanisms will be disassembled and cleaned.

I started by pulling the playfield out of the machine and prepping it to go into the rotisserie.

Once the playfield is installed in the rotisserie it’s MUCH easier to work on. There are many areas on a playfield that are hard to get at with it installed in the machine. A job like repairing all of the lamp sockets would be almost impossible with the playfield installed in the machine. The bottom of the playfield is also remarkably clean.

I setup the machine so I could plug the playfield into the head and run all of the lamps and solenoided with the playfield in the rotisserie. That means that I can test everything thoroughly and make sure that the playfield is working perfectly before putting it back into the machine. Working on the playfield in the rotisserie while still being able to test it electronically is the best playfield restoration method I’ve tried thus far. Not only is it far easier to reach many of the parts but you also end up with a better result in the end because greater detail and care can be taken.

This is not the first time I’ve seen this trick. Someone installed some electrical tape to try to keep the lamp sockets from vibrating around and losing contact with the base causing a non working or flickering lamp. I can’t imagine that this would actually work but I’ve seen it on a few machines. The only way to really fix the problem is to solder the sockets to the base. I’ll cover this in the next part of this restoration log.

the rest of the pictures show detail of different parts of the playfield. These will be useful in reassembly but I always make a map for myself on paper of where the different types of screws and posts go.

It’s difficult to find a Nine Ball machine without wear in this area.

In this picture you can see where one of the lamps partially melted one of the green lamp inserts. I considered pulling one out of my other machine but I didn’t want to get into swapping lamp inserts around so I left it. Not something that the average person will notice right away but it’s a shame to have an imperfection in an otherwise perfect playfield.