You already mapped out exactly what you need to check.
Start checking diodes, bridge rectifier and see what you get from there.
-Mike

I think the most likely suspect is going to be that transistor. I'd check that first.

Have you recently unplugged any cables? I'd check to make sure that you have the plugs aligned correctly and not shifted by a pin. I'd also check the bridge rectifier.

And the transistor?

One more thing to check is the coil itself. It could have an internal short which is causing the fuse to blow when it activates.
I've had this happen on several games, mainly on pop bumper coils. If resistance is too high or too low you can have problems.

Short of a catastrophic failure, you won’t *see* anything wrong with it. You have to test it.

Nice, so problem solved?

Is a coil stuck on startup of a game?
I'm currently working on a Whirlwind and because of a stuck popbumper, a fuse on the aux power board keeps blowing.
Maybe you've got the same problem

Snip the single wire to the coil. Then power on.

Most likely one the two diverter coils is locked on. If it was one of the other coils it would burn the fuse in one second. Look for a shorted transistor in the special solenoid section. You don't need to remove the board for testing.

You have a shorted transistor. Disconnect these 3 connectors in the pic below. Use a DMM to test the 22 drive transistors to find the one that is shorted.

Do you have a DMM? Do you know how to use it?

CPU (resized).PNG

Those two rows of transistors are to control the computer controlled lamps. You need to look at the transistors next to the red circles on the pic I posted. Place your DMM in ohms and stick the black lead under the ground braid that is stapled to the wood of the back box. Then with the power off use the red lead and test each of the 22 transistors metal tabs. Note the transistors number that has a low resistance. Let me know what you find.

I had a similar issue with my f-14, the coil would lock on at startup. It ended up being the diode on the coil.

Did you remove the 3 connectors before testing?
I colored your list, green circles are good readings.
Red circle looks bad to me. These are the diverter coils.
If you cut the blue/black and the blue/green wires off of the divertor coils and insulate with tape you should be able to replace the fuse and turn on the power with out burning the fuse.

coil (resized).png

list (resized).jpg

Leave all 3 connectors off, replace the fuse. Turn on the power, does the fuse blow now?

Well then you have a short on the purple/yellow wire. Not that easy to find. With the fuse removed and the 3 connectors removed, connect your DMM to the purple/yellow wire on one of the affected coils and black lead connected to ground. Set DMM to diode test. Your DMM will be buzzing because there is a short. Now start looking for a pinch wire or a broken wire that is touching metal or the ground braid. If the buzzing stops while moving the wires around, keep looking for the problem in that area. It can be as simple as a coil lug is touching a lamp bracket. Once the metal lamp bracket is bent away so the two aren't touching, problem solved. F-14 is very tight under the PF and things get bumped when serviced.