I recently picked up a Flash Gordon that needs a decent amount of work. I noticed that the leaf switch that activates the upper right mini-flipper (the switch that's on the stack on the lower flipper) had literally fallen apart, so I replaced it with a new switch last night. It worked fine, but after replacing it, I noticed that my EOS switches on both lower flippers were arcing pretty badly. The switches looked terrible, and since I had two extra EOS switches in a rebuild kit I ordered, I went ahead and replaced them. After replacing them, I found that the brand-new switches were still arcing pretty badly, maybe even worse than before. I adjusted them, thinking that maybe the problem was that the EOS switches were opening too early. After adjusting them, I turned on the machine again and tried to play a game. The switches were still arcing, and after about ten flips, both right flippers stopped working entirely. Even more ominously, at the exact same time, the machine started making a buzzing (or maybe a very rapid ticking) noise when I hit the right flipper button. I wasn't able to pinpoint where the noise was coming from because I was afraid to hit the right flipper button any more than necessary out of fear of damaging anything further. It's also worth mentioning that every time I hit a flipper button on the machine (even before I replaced the switches) the incandescents dim momentarily, although this was made worse by replacing the switches. After the two right flippers stopped working and the buzzing/ticking noise began, I turned off the machine and checked all my fuses (including the one under the playfield). All of them are fine. Does anyone have any suggestions? Thanks in advance!

Yep, I'm still using the original linear hardware. I did some research on this after reading your post, and I'm thinking converting back to the older rotary style is the way to go. As far as what's causing my current issue, is it possible that my right coil got fried? I'm relatively new to this and I've never had a coil fail before, so I'm not familiar with the symptoms. I know that when a coil does fail it just stops working entirely, but could it possibly cause that weird buzzing/ticking noise and dimming lights?

That may be my issue; I'll have to investigate after work tonight. Thanks!

I solved my issue, and it's so incredibly dumb that I'm ashamed to share what I did, but maybe it'll help some other poor sap in the future. Since I didn't have a double-stack switch for the bottom right flipper, I Frankensteined together two flipper switches, one of which I had to take apart to remove a layer from the stack. In the process, I managed to make it so that the back of the contact on the lower right flipper switch touched the back of the contact on the upper right flipper switch, which caused the coil to seize up. I fixed it tonight and everything works again, although I'm still getting sparks. I'm definitely planning to add caps to the switches at the very least.

Thanks! I'll tinker some more tonight.