Out of town Blackbeard, but if you don't get help by Tuesday I'm up for helpin.

I put this in another thread but. I had this issue when the ramp diverter coil was bad or partially connected. It was like the game was expecting to have to kick the ball out too you but the ball passed all the way through the ramp to drop at the upper left flipper. IDK if this is similar enough to your symptoms but it was an occasion when my old HS use to random fire those same UK's.

Best of luck with your repair I will be interested to see what turns out being the problem.

Yeah the wire came loose on the coil. I tested the coil and hooked it back up. Diverters worked fine. I do not remember specifically having the random UK firing after that.
My siren was connected and working at the time. All other gameplay seemed unaffected.

Hey Blackbeard, I just verified on my High Speed that no, I don't get any coils firing when I run the red light, regardless of whether the beacon is connected or not.

How often does your left hideout coil fire when this happens? The playfield flashers (top, both sides, and the two under the blue inserts all take turns flashing at a rate of maybe once a second when I run the red light, so if you coil fires at about that rate it may point toward a short with some of those like I mentioned -- if not then maybe that tells you to look elsewhere.

Keeps us posted I am curious what the root cause is also.

Checked mine too and no firing coils.

Since I own the machine I want to know as well, it has me wondering what it could be.