MTH Z-4000 Transformer Issue

Yes, there are calibrations, but it seems odd, both got knocked out together.  Was this dropped or jolted?  You need a long 3mm Allen key to remove the screws to open the case.  Each throttle uses a 0-10K Pot that needs to read 0 ohms at the 0 Voltage reading.  G

GGG, are there any schematics on line for the Z4000?  Or internal oictures?

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.

John,

The more I think about it, it seems like a problem common to both sides.  That would put the problem before the power is distributed to both throttles.

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

Why is this a problem? 

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!

Thanks, FEC fan.  It's not a high priority item, but when you get around to it, might be informative.

Thanks, GRJ.  Looks a bit more complex than my ancient PW ZWs.

Just a bit.

John,

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.

Try resetting the breaker up front on the side. There are 4 in total.

I am George not John.  May be one of the power FET failed.  Yes I can trouble shot and repair.  E-mail is in my profile.  I would check the breaker as Joe recommended.  G

I can repair it, but I'd suggest finding a local MTH shop as the shipping two ways will be pretty stiff for something this heavy.

I would have the engine checked out as well. It should not be running at over 20 volts. More like about 12.