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Upon power up ( the main switch) one of my Z-4000's displays 1.6 V in both throttle windows.  Checked with a DVM - 1.6 v actual.  10V and 14V fixed outputs read ok.


Is there a way to adjust the throttle knobs?

 or - is this a job for a certified technician?

How do you get into a Z-4000?



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No, the transformer was on the floor, used to run an MTH Standard Gauge Blue Comet Set for the Holidays.  The locomotive has the original lionel type motor, no sounds and needs about 20-21 volts to run.


Only one side was used.  After starting up the other day, the locomotive stalled and would not run.  Got the RED lite, shut everything down.  Dismantled and put away the set.


Upon powering up on my work bench later, both sides read the same.  Something must have been nocked out of calibration, both reading the same.  Checked both outputs with throttles OFF, both read the 1.6 volts (same as indicated on the windows, both sides).  Never dropped, jostled, bumped or anything like that.


At this point I really do not want to go into the innards not knowing what I might find and do not want to mess things up any more than necessary.  But I guess I have to.





I am imagining this is an electronic issue after the short.  I would break out the engine and test with a different transformer.  If it runs fine, you had a casualty to your Z.  I don't think it is the calibration. 


RJR, no schematics on the web.  Some basics the techs can do, and beyond that MTH recommends it goes back.  I would call and describe symptoms to a MTH service tech, and based on that proceed.  Normally you don't see a lot of issues with the Z-4000.  G

GGG, I'm not having any problems.  But I am familiar with the guts of the postwar ZW and, realizing that the Z4000 differs internally, would like to know how.  For example, how many secondary windings, how is/are breaker(s) located in circuit(s), how is output voltage altered, does output voltage retain a pure sine wave at all voltages, etc?

RJR, there are partial schematics in the Z4000 patent. I printed it out a long time ago-- it's over 40 pages! I'm at work, so I don't have the patent number handy. If you and anyone else is interested, I'll post the number to this thread when i get home-- EDIT: I just did a patent search using the assignee name "mikes train house". Found the Z4000 patent and the rest(DCS, etc) . Z4000 patent number is 6,281,606 granted Aug 28, 2001. there is a full text description and also all necessary images availabl as PDF files. Enjoy!



The locomotive in question is the Standard Gauge Blue Comet Reproduction by MTH 1996 or so with Bild-A-Loco motor.


I did what you suggested:  Used another Z-4000, locomotive ran fine, both Track 1 and Track 2.

Powered up the same locomotive on suspect transformer, Track 2 power - works fine (but when track 2 lever is shut off, still reads 1.6 volts).


Powered up on Track 1 of suspect transformer - BINGO - nothing.  No response.

Appears to have nocked something out on the Track 1 side.


Can you repair?


This is way beyond my expertise.



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