If you clip an alligator jumper to the metal tab of Q17 and *briefly* touch the other end of the jumper to the ground strap, it should fire the coil...does it?

I'll admit, I'm stumped! It's passing every test I would normally run to narrow down the suspect. My only other guesses would be to try reflowing the solder for 2J11 on the driver board (or possibly replacing the male header for that connector if all else fails), and if that still doesn't fix it, maybe it's a problem with the female connector going to it...or possibly an issue at the connector between the cabinet and backbox, one of those big molex block connectors. The manual is calling it 8J3/8P3, you'd have to look carefully for the gray/red wire in the harness. I would think the test you just did would eliminate all those suspects, but you never know...

I'm not sure if any of that will yield the solution--but that's the stuff I'd try next if it were my game...

Good luck!

I don't think that would affect the coil though...it won't even fire in coil test, which eliminates switches from the equation. You can also try running the switch test and verify the switches are putting up the appropriate number on the displays when activated during the test. The manual should have the specifics to look for.

Seems we've probably narrowed down the problem to only a couple things at this point. Granted the wiring and connectors are indeed fine, there's only 2 other places I can think to check: The 7408 chip on IC1 on the driver board, and the 6821 PIA on the driver board. Since Firepower 2 has no coils for solenoids 5-8, you could even swap the 7408 at IC2 with it.

Here's a couple pics for reference, IC1 highlighted with red, IC2 with blue:
Screenshot_20230420-064443.pngScreenshot_20230420-064333.pngScreenshot_20230420-064303.png

Edit: one last thought--it would be a good idea to verify the traces have continuity between all the components in that particular circuit (between the transistors, resistors, chips etc involved) before changing out any chips. You can also test the 7408 with a logic probe and the game in solenoid test.

Jeez, I must have written my edit the same time slochar came in with that helpful info.

Anyways, follow his instructions--that should lead you to the culprit...

Perhaps you've got a stuck coin door switch? Once the game is in switch test, try unplugging the 24-pin molex connector for the coin door (inside the cabinet, somewhere near the start switch)