Z4000 Trouble Shooting

If the z4000 throttle gear has slipped inside and is not fully closed you will get a short light! the metal bracket sometimes get bent and the gears slip off each other and get out of time. there not easy to take apart and I would not recommend trying unless you know what your doing , you can damage the unit inside and the harness's are very short and easy to pinch a wire !

also MTH will only sell transformer  parts to ASC TECH's

Alan

@Alan Mancus posted:

also MTH will only sell transformer  parts to ASC TECH's

I'm guessing that policy may have changed since they're going to be selling all the other electronic parts to anyone once they're back in stock.

Have to remove all the allen screws from the bottom of transformer.  Metric.  Some may have been phillip depending on production run.  Handles up and top comes off.  Need to observe where harness go and how they are oriented on top.

As far as handle there is a set screw on bottom of handle on later models to control friction on handle. G

Thanks all for the replies. I did not get any notice of your posting and only saw them when I posted an update.

Z4000 repaired!

Once again thanks for all of your replies.  Turns out the right handle worked itself loose and only partially engaged the throttle gears. Once that happened the potentiometer would not rotate to the zero position. The Z4000 would turn on but not leave the "short" status.

This Z has set screws to adjust the handle tightness on the underside of the case. I guess one had worked itself loose and allowed the gears to slip - causing the problem.

The contact between these two white gears is adjustable through the set screw. Backing it out most of the way  I was able to rotate the smaller gear to a zero or off position without moving the handle gear. Once set, the handle was rotated to the off position and the set screw re-adjusted bringing the gears back together to mesh. Since both potentiometers were now at zero, the Z started up normally. Funny how something so simple causes the Z to stop working - I suppose its a safety feature.  In my opinion this gear design provides a lot of sloppiness in fit and ensures the pot will eventually work its way into a non-zero position and show a fault. Expensive to ship and repair - and unnecessary since nothing is really wrong with the transformer.   

CAUTION - as mentioned in the comments, the wiring harnesses do not leave a lot of room to move things around, be careful in lifting off the cover. While you can disconnect the harnesses from the cover you really do not need to do so in order to re-align the pot gear. You will need a long hex key (allen wrench)  to remove the 7 screws holding the cover on. Mine were barely finger tight.  Remember to pull the power plug before opening this up. I put the cover back on without the screws to make sure the pots were zeroed, powered it up to make sure it worked, pulled the plug and then screwed the cover back on. Also be careful on handling the cover and base, I find it is brittle and found some pieces broken off internally. 

Thanks to the following for their help

@gunrunnerjohn  @GGG  @Alan Mancus