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Fans not turning on

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Posted · Fans not turning on

Hello all,

I am using my ultimaker for the first time today and yesterday, trying to get everything dialed in to work properly, but I cannot, for the life of me, get the 2 side fans to turn on!

I found http://umforum.ultimaker.com/index.php?/topic/3963-left-fan-not-working-on-um2-resolved/ where the resolution was that the loop wire was connected red-to-red or black-to-black. That does not seem to be my issue; my loop wire is connected red to black, so the fans are, in fact, connected in series.

I ran a test print just now where the fan settings were overridden to turn on to 100% after 0.1mm in height. I disconnected the headers from both fans, and measured voltage (DC) across the power source: nothing. So the issue seems to be before the fans somewhere.

Hoping someone has some guidance before I start disassembling this thing.


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    Posted · Fans not turning on

    Does the fan on the back of your print head come on properly? The next thing to check would be to look at the other end of the wires, under the big cover below the printer. It's held on by two screws that go into lock nuts on the lip of the cover. The head fans plug into a connector at the side of the board, near the frame.

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    Posted · Fans not turning on

    The easiest way to "turn on" the fans (of course it won't work but you need to do this to test) is to select PRINT, then select any model then quickly go into the TUNE menu and then go to fans and dial up to 100%. As long as you stay in the TUNE menu then the printer will not start printing. As soon as you exit the TUNE menu it will probably start printing so instead just kill the power.

    The power for the fans is very tricky - I'm not sure how good you are with electricity but if you measure at the print head you need to disconnect both fans and measure the two connectors *not* connected to the loop wire. There should be I think 24V there (or maybe it's 5V or 12V - there are 3 common voltages but I think the fans are 24V across both fans or 12V each).

    If you take off the bottom cover (isn't it just one screw Illuminarti?) I believe the fan signal is the top left connector in this photo labelled "fan pwm" (partially obscured in photo):


    Those fans are very important to get quality prints.


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    Posted · Fans not turning on

    Yes, it's 24V across both fans, and as you mention, it has to be measured across the two wires coming from the electronics board, ie the one pin in each connector that isn't the green jumper wire that joins them.

    And no, there are two screws in all the recent machines I've seen - maybe it used to be different, but my personal printer came without a cover anyway.

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    Posted · Fans not turning on

    Howdy folks,

    As it turns out, the wire connecting to the PCBA below the unit was disconnected during shipment. Thanks for the advice.


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