Well as I had posted recently Dr. B Zarr's head no longer follows the ball . Wherever I manually turn the head  it would just go all the way to the right and stay there on startup.  However he does still move his jaw when he speaks. Head test fails.

I tried a few things...head position optos all tested out OK.  I had misread  Clay's instruction on checking transistors so I wasn't sure whether the transistors were an issue or not as my test method was incorrect.. Anyway, I wound up swapping Q32 and Q34 which control head direction and head movement on/off. My soldering sucks and one of the leads on one transistor may now have a cold solder joint. If I had a schematic I could check continuity with a DMM but I cannot find a shematic on short notice. It is very difficult trying to see where the trace to the middle pin on Q34 is supposed to go to.

Dont know what to check on the high power board located under the playfield except connections, and all appear to be good everywhere.

Here is my dilemma:

Due to the transistor swap and possible fault there, the head now doesnt move at startup. In a way that's good so at least it will look straight ahead and I don't mind that. However as a keeper of a dying breed (pinball and Party Zone) I feel I should get it 100% for no other reason than to preserve the machine as it should be. I cant figure it out on my own and I am not an electronics tech.

What should I do?

1- bookmark this: http://files.flipperspill.no/Support/Pinball/Pinball_Manuals.htm
2- check the schematic and ask before doing something.
3- Aren't you happy it has a translite and not a real backglass?  

Thanks , but just like everywhere else they have the manual, operator manual, and NO schematics. Ho hum.

I haven't looked at a PZ in a while but your problem to me sounds like you are having a problem with the gearbox rather then anything else.

I think I remember the head being hooked up to a gearbox/motor.  If you can move the head manually left to right while connected to the gear box without really having to force it then your gears are stripped.  A good gear box, you should not be able to move the head at all without really forcing it.  You should never try and move anything manually connected to a gear box as that is how you break it in the first place.  

The head moves freely left to right when I try. You can hear gears turning and there is some resistance, but it is smooth in either direction. It feels like they are ok. Pretty sure it is an electronic issue based on sound/feel.

Nope, you shouldn't be able to move his head at all if the motor and gear box are installed correctly not without really forcing it.  

I'll check Mike's PZ when I next see it to confirm but every other gearbox/motor assembly works that way.  Things Hand on TAF, Cyro-Claw on DM, Mist Motor on BSD, the Reel on Fishtales.  I've worked with all of those and they all had motor/gearbox combos and you could not in any way move the assembly without really having to force it if when the gearbox and motor were installed and if you force it, your going to break the gearbox.    

It does require some force but I move it slowly and certainly you can hear there is a series of gears moving which creates the resistance. I dont see/hear any evidence that the motor is turning with an internal gear issue. I will try a head test while checking voltage change at both terminals of the motor, but Im sure its not activating at all.

Quoted from wbradley

Thanks , but just like everywhere else they have the manual, operator manual, and NO schematics. Ho hum.

Have you ever bought a manual and scanned it? did you do the schematics too?

right.

didn't think so.

I downloaded and printed the manual the day I bought the machine and got into mess at work for tying up the printer on payday. Schematics on other WPC machines I have are huge and unfold like a newspaper.

Anyway, there were no schematics in it and everywhere that has the manual downloads does not include the schematics.  Anyway, thanks to Grauwolf I now have the schematics  in PDF so this will be a fix eventually.

Might need to learn a bit more about using the DMM, but thats just a matter of time, which in my case is scarce. In fact ,I'm still at work now. Also need to get a better soldering iron with new tips and stop using braid to remove solder...suction is probably better.

As you now know to repair a WPC you require the specific machine manual plus the generic WPC manual to get the full picture.

http://www.pinrepair.com/wpc/wpc-89.pdf

Got both! Thanks.