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My cooling fans on mt 2+ will not run. This was built from a kit and im guessing the fan connection on the mother is in the wrong place. What terminal is the correct one for the fans?


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I believe this manual will tell you where everything gets connected:

https://github.com/Ultimaker/Ultimaker2/blob/master/um2 assembly manual V1.1 _english.pdf


Note that the 3rd fan - the rear fan - only comes on when the um2 is hot.  Is this a um2?  If the side fans don't work it's usually the connectors just above the print head in the sleeve.  Sometimes a wire will come out.  The side fan connectors are connected together with a short loop wire - typically green.

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Thank you for the reply.  I have the manual and have the fans connected to the terminal in the instructions.  I am going to verify the connections are good and that the voltage is correct going to the fans. Not sure if the two fans are series connected or parallel connected but if I have voltage i can work that out. This is a new motherboard as the original burned out. So I added a cooling fan to the board enclosure and made feet for unit to raise it up some. the 5volt fan works fine. There is another voltage connector on the edge of the board (24 volt) but I have not determined if it is on full time or software controlled. Never short of challenges with this machine.

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Update on what I have found. The good news is the motherboard is doing its job. With fan speed set at 100% and head temp at 200c I have 24v at the fan connectors. Backing the speed down to 50% shows about 12v. At your suggestion I checked the wiring at the hot end and it was wired incorrectly.  I removed the fans and connected a 9v battery to the fans and only one worked sometimes. If it would not run and I hooked it up reverse polarity for an instant it would then run with proper polarity. I have another complete hot end and neither fan will run on their own with a 9v battery. So I have ordered 4 new fans.  I will wire correctly and see what happens.


Thanks again for your input. 

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