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Nozzle does not stop heating, UMO


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Posted · Nozzle does not stop heating, UMO


I have problems with my nozzle and the temperatur.

The nozzle heats up, but it does not stop heating. Last time I needed to replace the thermocouple as it was destroyed because of the extreme heat. Then I changed the thermocouple and I could print again. This morning I wanted to print again, but same problem, the nozzle heats up without limit.

At the ulticontroller there is no display about the actual nozzel temp it just shows 20 degrees, which can not be true.

There is no errror massage at the ulticontroller.

Could anyone please assist me to get this work again.

Kind regards




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    Posted · Nozzle does not stop heating, UMO

    Did the thermocouple fall out? Check that first.

    There are many things that can cause this so you need to isolate.

    Measure the voltage coming from the top of the head. The voltage should represent the temperature "directly" like this:




    Then heat up the head so that it feels warmer (at least 30C) and measure the voltage again.

    If the voltage is correct (voltage goes > 300mv) then the problem is in the cabling or underneath the UMO. If the voltage stays at 200mv then the problem is at the circuit board or the thermocouple. This is a first isolation step.

    If you don't have a voltmeter, find someone who has one and have them show you how to use it (have them do the measurement!).


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