Make sure tz has her own plug all to her self. Test the plug see if enough power coming through. If that don't do it. Then Id say rebuild your bridges and caps on your power supply board.

Before replacing the bridges and caps (BR2 and C5), reseat all of your connections on the left side one your power driver board (J114, J116, J117, J118) and the z-connector right before J117. A corroded or loose connection can cause a reset too.

The phantom switch issue might be related, or maybe just a bad diode. I would see how it reacts while in switch edge test mode.

I agree about reseating connectors first before going all in and replacing stuff. In addition, I'd reseat J101, J102 as well as the ribbon cables and switch connectors at the bottom of the CPU board. If the problem goes away but comes back down the road, at least you know it's just a connector somewhere that will need to be addressed.

Check the switch matrix in your manual. See if the clock, VUK, and spiral switches are related in any way.

They could be on the same row or column. At the least, it might help you narrow down your search.

You'd be surprised what a broken diode, stuck switch or switch lug touching metal can show up as during game play. Switches that are seemingly unrelated can cause issues in other areas of the game. It always affects other switches on the same row or column though but can make modes start and balls lock without doing anything to qualify them. I've never had a logic issue on a game that wasn't caused by some sort of switch issue.

It's a pretty popular topic...

read this: http://pinwiki.com/wiki/index.php?title=Williams_WPC#Game_resets

faz

If you decide you need some videos to help you with troubleshooting, I highly recommend getting access to Clay's pinballninja.com blog for $20 (details: http://www.pinrepair.com/donate/). I'm not in cahoots with Clay or anything, and I'm not knocking pinwiki, but Clay's videos are really good. There are a lot of videos on there where he troubleshoots and fixes WPC resets. I just searched "tz reset" and found seven videos specific to TZ.

Perhaps your game has two separate problems.
For the reset problem, just work through the PinWiki steps.

But first I'd work on the apparent switch matrix issue that you have. Place the game in switch test (T1), and test the flipper cabinet switches, inlane switches, and whatever else you've noticed is odd. I would test your opto switches too. The behavior you note makes me suspicious of the optos.

--
Chris Hibler - CARGPB #31
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http://webpages.charter.net/chibler/Pinball/index.htm
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Make sure you didn't miss or bend a pin when reseating those cables. That can cause some wonky behavior.

I suspect the unregulated 12V supply. It would explain the otpos triggering when the clock is running, because the clock runs on 12 volts. With the extra load, the supply dips down to where the opto emitters are too dim for the photo transistors to see. The same thing happens when both flippers are pressed, because they load the entire game down. Check the 12 volt connectors at the bottom left corner of the driver board. Since they are only 4 wires each (some have fewer), the wires tend to break right at the connector. If you have a voltmeter, check the 12V on the board.

As for resets, I've had more success changing the LM323 regulator than swapping out BR4 and C5.

Allan

My TZ was resetting. Plugged in Kahr daughter board ($30) and no more resets. If interested, search forums for Rob Kahr Daughter board.

This board fixed my reset problem too.