ISCSEMI-TIP102-pinout.jpg

Think of a transistor as a diode with three pins for testing purposes. On all transistors, the arrows on their data sheet will indicate that electricity should only flow in that direction, identical to a diode. With your meter in diode test mode, put the black probe on the base pin 1 (left) and the red probe on the emitter pin 3 (right). If you see zero resistance on the meter, the transistor has shorted. If that checks out okay, put the red probe on pin 2 (middle), and the black probe on pin 3 (right). Again, if you see zero resistance, it is shorted. You should see infinite resistance in both of those tests, just like a diode would if you try to go in the opposite direction.

That diagram may look a little confusing, to explain better, this particular transistor is called a Darlington pair. It is just two transistors sandwiched together in one little package.

Keep in mind those instructions are specific to testing TIP102/122/36 transistors. The pre-drivers and other transistors on your machine have a different pin-out, but the testing and information I gave you still applies.

The blue box thing is most likely a relay. Take a picture of the board and upload it so we can help you better.

What you are seeing there looks like there was PCB trace damage, so the person used the leg of the transistor to connect directly to that pre-driver transistor above it. Nothing really ghetto about that unless the underside of the board also has traces/connections that have been disconnected/neglected. Judging from the flux around that transistor though on the pads, it looks like a good candidate to replace anyway. I would test the pre-driver transistor that is just above it as well, these parts often fail together. When you desolder and replace that transistor, you can either bend the leg again and resolder it onto that trace, granted there are no traces on the opposite side of the board for that pin, or you can put the part through the original holes and run a jumper wire up to that pre-driver transistor. I prefer to run jumpers, but it is really personal preference.

The buzz is normal when lights turn on and off on all machines. It lessens when using LED bulbs as less current is being drawn.

Above each of those TIP102/122's is the pre-driver transistor. If both test out okay and aren't shorted, and you are reluctant to try and remove them, perhaps you can ask someone else to help that is nearby.

If I were dealing with this issue of yours, I'd first make absolutely sure that I have my coil wiring done properly. Then I would just go ahead and replace all 6 of the TIP102s along with their pre-drivers. Why? Because $4 worth of parts and 10 minutes of board work is easier and less expensive than dealing with $2 fuses blowing each time I turn the machine on while trying to guess which parts are bad.

Use Slo-Blo everywhere would be my guess. I haven't come across a pin that used anything else.
The Relay is soldered in place. It is the flipper enable relay, it is probably working fine so I'd leave it alone.

Collin, nice collection. How do you like the Bad Cats? I've always wanted one.

Get something with an adjustable temperature or minimum 25 watts, otherwise you'll end up with cold solder joints and lifted traces. After a year of using a crappy radioshack iron (15-watt), my dad-in-law gave me his Weller WES51 station and I realized soldering wasn't so hard after all. Flash forward a decade and hundreds of projects later, and I'm still using that equipment.

Best advice I can give - For small solder pads and components, if you have to hold the iron down on the pad/component for more than 3 seconds to melt the solder, it is too cold. If it melts instantly or smokes a lot, it is way too hot. An adjustable iron comes in handy when you're working on large components (like these transistors), jacks and switches that require substantially more heat to melt solder properly. Even with the added heat, larger components will take longer to melt solder onto (sometimes several seconds before it starts flowing). No worries for switches and jacks though, as you can't really damage anything with heat. Always apply heat to the pad/component first for a second or two, then melt solder onto it. The end result should be mirror shiny, not dull or grey looking. If it isn't shiny, it is too cold. Also, don't put solder on the tip then place it on the area unless you are tinning a wire. Good luck!

That is correct for coils with a single diode, but it does matter for coils with two diodes.

Can you manually push the bumper coil up and down with it out getting stuck? If you can't, you may need to replace the coils & sleeves for them. They should move freely with no friction.

I'd go to the schematics at this point. Both switches and coils are wired in a matrix. They go in chains and overlap each other. Switch matrix issues won't cause fuses to blow, but coil matrix issue could. You may have a bad diode in another area on the same line as the bumpers that is causing them to stay on. I don't know for sure because I didn't check, but it is likely both pop coils are on the same row or column of the matrix. Inspect the diodes on the other coils/test them in diode mode on a meter.