Thanks in advance for any help. I am a total novice at repair.

I just picked up a Tri Zone that functioned fine for a week or so. Now all coils quit at once. I suspected a fuse, but looking at the schematics, the coils for the flippers are on a separate fuse from the rest of the coils. What are the odds that both fuses failed concurrently? I should be looking farther upstream, I guess, but where?

All switches and lamps are still functional.