Okay, I'm lost here, going nuts, and requesting some help.

Every few (like two or three) games my TZ will report "Check Gumball Machine Diverter" and default to simulated powerballs. I can sometimes fix it for a couple games by starting a game with the glass off, manually hit left then right ramp and then load the gumball machine. A few normal games later TZ will return to believing there's a problem and back to simulated powerballs it goes, even though balls are diverted where they need to go. I cleaned the opto before the vertical upkick into the GB machine and the switch in the small trough leading there performs properly in testing. As far as I know, these are the two main areas past posts here and and in rec.games.pinball have pointed to as problem ones. Both the subway and trough sensors are able to differentiate between regular balls and the powerball properly.

I don't know where to go from here - I'm so close to having TZ function at 100% but the powerball is such a big part of functionality and personality of the machine.

Any guidance would be greatly appreciated!

Thanks for the reply!
This is what's frustrating me. From old discussions I've read, it should be either the small trough switch 51 or the kick up popper opto 74. In test, 51 registers when activated and opto 74 is cleaned and closing when there's an obstruction, so I don't know where to go from here.

Would you suggest just shotgunning it and replacing both and see where I am from there?

So far with finger. I take it this is a rookie mistake! I'll get a ball through the trough tomorrow in test and check back. Thank you again for your indulgence!

Right before reading your post, Coyote, I happened to do just that - I let it go about 8 times and was getting discouraged as all the switches seemed to be triggering as they should: spiral, lane, popper, entry. And then a cycle completed without the spiral switch activating. I cleaned it, noticing a decent amount of dirt came off. "Played" a game activating gumball and rolling the ball up the orbit. It loaded, dispensed and cleared the credit dot.

It's done this many times before only to come back, but seeing the spiral switch fail to register gives me some hope. Also, I didn't know that the continuous gumball test will eventually report a suspect switch, so that's great to know.

Thanks to you both for your help! I'm gonna keep watch and will see if a bit of grime was the source of my problem. Otherwise, I'll be asking to bend your ear again!

It's really a bit maddening! I understand TZ is a beast of a machine for a home owner new to keeping them functioning and I'm still having a lot of mental block coming to terms with how the machine decides things are or not working.

I haven't had the luxury of playing much at all tonight so I still have that sinking feeling that the check diverter error will show up again as soon as let myself believe it's sorted. but here's hoping!

Update for those who are as novice as I am and frustrated when googling for similar possible cures.

As feared, the "Check Gumball Machine Diverter" error came back within a few games so I ran another course of gumball tests. Switch 51 didn't fire reliably and so I bent the actuator randomly in a way that I would hope would activate whenever a ball went down its short trough towards the gumball popper.

A few games in and so far everything's working as intended, though I reserve the right to resurrect this thread should the error resurface.

Thanks all.

As a novice in owning such a temperamental machine as TZ, this is really useful information because, of course, I immediately jumped in to bending the actuator, aiming to shape it into something the ball activated. Thank you.

Regarding this particular switch, it looks like I lucked out and got it in to a passable position as I've been playing all evening and the gumball diverter error has not returned and the powerball is working as intended. Regardless, I'll remember your instruction the next time a microswitch is bugging out on me.

Thanks everyone for their help and hopefully this problem has been put to rest!