I recently dug this pinball machine out of the back of a storage room. It hadn't been touched for at least 15 years. It did boot up, but the triggers were non-working or delayed. There was no sound. The display was a garbled mess. Many of the bulbs weren't on. Rubbers broken and fallen off. But on the bright side both flippers worked and it did sort of start the game up.

I talked to a local pinball repairman and he basically said I'm probably looking at paying him more than the cost of the machine to fix it up. This is exactly what I wanted to hear because it means I get to start messing around with it guilt free.

5AKvWLJ.jpgq154R8Y.jpg

Part 1:
The guy I talked to mentioned that very often the battery on the circuit board will leak and cause a bunch of corrosion. (That primitive old thing has a circuit board in it??). After failing with all of the ~30 assorted keys that were in the room I gave up and drilled out the lock. I didn't have any idea how to access either part of the machine so I actually had to ask a friend for help just opening it up. Eventually he was able to walk me through it.

This is what I found lurking inside:
GDafHfkl-646.jpg
pfwQbPm-143.jpg

I was very eager to get rid of the corrosion so I yanked off the battery leg with pliers:
T0UZAMhuE1HyuIyWoy4p4OoXrzA-680.jpeg

Part 2:

Yes. It was really dumb but I didn't even know what solder was at the time. I did some reading and ordered a soldering iron and the System 80 repair kit from great plains electronics [http://www.greatplainselectronics.com/proddetail.asp?prod=GTLB80-BA-KIT]. I washed the board in vinegar and alcohol using a toothbrush and cotton balls then sanded it down with 220 sandpaper.

I think I managed to get rid of the corrosion, but I'm confused when it comes to fixing up these traces and pads. At this point I don't think I even want to replace the battery and the pad it was on because it seems overwhelming. Will this actually affect gameplay? I don't really care about high scores.

The pictures below show where I'm currently at and I have a lot of questions.

I plan on soldering on replacing the vertical trace by soldering the lead from the new resistor onto the other end of the trace(Pitiful amateur hack maneuver??).
Do I then run jumper wires from each component to the ending pad?
Is 22 gauge OK?

I also noticed another pad that was either eaten through by corrosion or damaged by my amateur desoldering.
How can I tell if all three of those pads were originally connected?

POUSmqx-966.jpgYSUIZAO.jpg

The edge connectors were also pretty badly corroded as well as you can see in the above picture. I used a pencil eraser, but it didn't do a very good job. Is it safe to sand those? The repair man I talked to said they were very fragile and very hard to fix, but I saw some sources online that recommended sanding. Anyone have any suggestions for cleaning those off?

I also ordered new pins and molex housing plus a crimper because I noticed some possible corrosion on the existing pins.

Small update. Finished all the board soldering. Went ahead and sanded the male edge connectors which look very good now. Hopefully I didn't damage anything.

Now trying to crimp is making me lose my mind. I can't get the pins to firmly grip the wire. I've never felt so incompetent. I will try again tomorrow.