MTH Z 4000 residual voltage

It is a quirk of the Z4000 display when the transformer circuitry is not under a functional load. If the transformer leaves the initial start-up, then there is nothing to fix at the potentiometers...
The displayed readings are never (hardly ever) 0.0V (no load connected at 0.0A) on any Z4000 (handles "off" position). Connecting a "phantom" load such as a lighted lockon or passenger car can reduce the apparent displayed voltage at 0.0A (handles "off" position), but the lowest actual voltage a Z4000 can deliver is 5V (handle position "on") with a "true" load connected (see manual). As such, this "loading" action merely changes the apparent output displayed at 0.0A but does not alter the overall function in any meaningful manner when under an actual operational loading condition i.e. a train.

The very early Z4000's would never go to zero   I suspect this is one of those early ones   The manufacture year is embedded in the serial number

I have one that does this and one that doesn't. If I put a true RMS VOM on them they read exactally the same so I don't let it bother me. I liked Überstationmeister answer it's a quirk.

bluelinec4 posted:

The very early Z4000's would never go to zero   I suspect this is one of those early ones   The manufacture year is embedded in the serial number

For future reference, how do you know which year or serial numbers do or do not have this issue?  I have toyed with the idea of buying a z4000 several times but never pulled the trigger.  I would like to avoid this issue if I can (especially because i tend to buy used equipment.)

Add a 18 v bulb across the terminals. The load will drop the voltage to zero or very close. Please post the serial number of your Z4K.  It's on the silver tag on the back of the transformer.

Chris

LVHR

Hi JHZ posted

For future reference, how do you know which year or serial numbers do or do not have this issue?  I have toyed with the idea of buying a z4000 several times but never pulled the trigger.? 

for what its worth purchase serial number later then 039 they mainly had the issue even though it don't really matter that much . just purchase newer transformer and you wont have an issue, they modified the boards in later versions to correct the issue. 

mth makes a very good transformer and was designed to work with there PS1 early steam and diesel locomotives! can be used to reset PS 1 engines when other transformers will not Run the ps1 engines. 

the serial number is on the back of the transformer if you need to check one out!

An MTH lighted lockon on each track brings BOTH readings to zero for me.

Thank you Alan