I am/was self taught. I owned my first pin (eight ball deluxe) about 20 years ago. At that time, there was no internet, only the blueprint manual - which I learned to read. I didn't have any "parts", but there was a variety of arcades, that had at least one operators that knew how to work on the pins. I would sometimes ask them questions, but for the most part, I would fix it crappily fix them with whatever sources I had available. I used (no laughing ) a Paper Clip as one (maybe more than one) of the switches that was broke. EBD was added with Dragons Lair and Lunar Landar for a trade (3 for 1) Gauntlet II arcade machine. About 3 months later it ended up at Scandia (which had no pinball operator) and it worked for about 1 month, and sat turned off for about 6 months, until they got rid of it.
I didn't own another pin 'til about 3 years ago, and have had about 8 different ones since. I now have none again.... I just don't have the funds available. I do have my Hyperpin, although, so I still get my pin fix almost daily
I recently obtained a T3 (trade for Need For Speed Underground) and it was in overall great shape. It was really, really dirty. The first Assualt multi-ball that I got caused a flipper to break. I fixed it correctly, then a day later, on my next assualt multi-ball, the other flipper broke. (Both were the plastic pieces of the flipper link assembly) I believe that the guy that I traded, didn't disclose that these were broke, and fixed it the way that hey knew how. Luckily, I had a spare set of WMS, so I put them on, and yes it needed a little modding, since the Stern and WMS flippers were a little different.
Big Thing, which is the KEY to self repairs..... Learn to read manual.
Search for item #'s, get correct parts, learn to solder (practice on junk parts first), always turn off machine while working on them.
After repair, or setting up pin for first time - have coin door open - this will prevent any major high voltage shortage - and test your switches.
Don't be shy, if you have an issue, post it. There are so many helpful people that have went through the same thing that you might be going through.
I had to take a pin to a repair shop once, and got it fixed, brought it home, and it was broke again as soon as I turned it on. I brought it back, and got it fixed again, brought it home, and opened coin door, before turning it on. I clicked a couple switches, and there was a column short. It was the second phase of my flipper switch touching a high voltage coil. This didn't happen at the repair facility, but did happen at my house due to the levelness of the floor. I remebered that I moved my pin prior to the initial problem, so I leveled my pin, then it was no longer touching. I put some liquid electric tape on the switch to prevent it from happening again.