Transferring from the listserv. Seems while I've been away from the hobby, a great deal of traffic has moved over here. So I'll try to see if you guys can help me out.

Hi Pin tech wizards:

Just finished fully rebuilding a Theatre of Magic. It LOOKS unbelievable now. But still doesn't work as intended. Generally works, but there are some gremlins flying around that are driving me crazy.

Here goes: Starts up, runs great. Plays fast as designed. Tested every switch, light, coil, and magnet. All work in test. All work in play... until she gets confused. Sometimes this can take a long time, and sometimes very soon. Usually long enough for you to think its fixed because of whatever I just did... to then sorely disappoint.

We are running TOM 1.2 and just did a full teardown of the machine.

When things get flaky, the trunk stops being wiling to move, or will be kept in the wrong state. Sometimes also - the trap door will keep one ball in the subway with or without the trunk flaking out. Finally the "open trap door" light on the ramp only will open the trap door half the time.

The only aberration I can find is that +18v on TP8 wanders from 14.7 and 18V. A wider range than I would expect. So I replaced the caps and bridge for the 18V circuit. (BR1). Didn't do BR2 as I had used my other spare for a stereo repair. But the 5V is solid. After the replacement, the voltage still wanders and the flakyness still happens.

Additional detail, is I can then go into test mode and find the trunk in an error position. But if I then do trunk test, I'm able to move it to a new phase with the buttons and once in a new position, the error clears.

Not sure what to try next. Any ideas on what could cause this kind of flakiness?

Thx

Skarv

Ps. Did Clay's recommended jumpers to the board while I did the bridge/caps.

Additional details from this evening and last night. Rebuilt trunk mechanism... cleaned, polished, tightened. Works more reliably... until it doesn't. Replaced the lock 1 switch, and replaced all 4 trunk optos. She still gets confused. Now I noticed too that you can get the metamorphosis ring to pick up balls occasionally when the corresponding light or challenge is not active. Very strange.

Tomorrow, I hope to swap the ramp switches and diodes. Will report back.

Got a suggestion of getting the 18V solid first, but I have to wait for parts to replace all bridges and caps before diving in there again.

Final symptom... when staring the machine and getting the chime... only the upper right play field GI lights up. Is this normal? Or an indication?

Thanks to all.

Thanks to all the helped with this one. She's up and running (fingers crossed). There was so much wrong with this machine, and some of it vexing. But a couple of late nights, and were in business.

First off... the source of the wandering 18v seems to have been several switches that had some current flow when open. Seems that some sort of goop was put on the machine at some point as this only affected the upper PF. Hence all the rust in that area. So I tested all the diodes and switches and found that the diodes were all good.. though one had a crimped leg, not soldered. But not all switches would drop back to zero when open. About 5! Replaced. Would be nice if the switch test was bit more sensitive so as to pick this up. Also, would be so nice if I could get the old Cherry switches so I could re-use the wire-forms. Anybody know of a source?

Then the final source of consternation.... the trap door test didn't work reliably. Seemed like the balls weren't being processed properly. But you couldn't really test because the PF had to be down. Thought the switches were hanging up the balls or something. Turns out that the plastic subway ramp had warped so on the rare occasion that 4 balls were in the lock mechanism, you would have the last one stay in the 'divot'. Took forever to figure this out, and a trunk removal to fix it.

In the whole process I also made my trunk more solid. The opto interruptor had cracked like I think every one ever made in 1995. Didn't want to wait for a new one so I took a hose clamp and drilled a hole in it where the allen bolt goes through. Snugged up the hose clamp, and then tightened the allen bolt, and it is like new. Hope this helps someone else with a TOM.

Thanks again folks. Wanted a TOM for a while so this is a long time coming... by the long road given the ripoff condition this arrived in.

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