Side fans not working, 0V

[diysystem 1]

Hi all.

I did buy a used ultimaker 2+ extended for a fraction of the price, lo and behold the printer has some problems.

Side fans are not working at all.. The last owner changed to 24V fans running in parallel 0.13A for some reason and probably fck something up.

Menu setting is always 0% on fan speed, if i turn it up to 100% and then try to print it has reset itself to 0 again. Go out of print > advance > fan speed > 0% again..

0 voltage directly on FAN PWM during print, even if i turn it up to 100%. Identical LED PWM is 19.8V.

Which part is broken?

Best regards

Edited May 24, 2017 by Guest

[gr5 2,172]

There's a transistor (possibly a darlington) that can break easily in this circuit. If you are good at soldering surface mount you could replace it. Did it come with the original 12V fans that were mounted in series? Or do you need part numbers or something?

Schematic for UM2 circuit board is here:

ULTIMAKER 2 SCHEMATIC - click "raw":

https://github.com/Ultimaker/Ultimaker2/blob/master/1091_Main_board_v2.1.1_%28x1%29/Main%20Board%20V2.1.1.pdf

[gr5 2,172]

Did you check the voltage at the fan pins on the PCB though? The wiring inside the sleeve is not dependable - there are little connectors in there and the wires can easily come loose that go to the fans. So check the voltage at the PCB first.

The easiest way to turn the fans on is probably to select PRINT, then select any print then immediately go to TUNE menu and then set fans to 100%. The printer will not start printing until you exit the TUNE menu. I think.

[neotko 1,417]

Check this post

https://ultimaker.com/en/community/21401-printer-head-fan-not-working

[diysystem 1]

There's a transistor (possibly a darlington) that can break easily in this circuit.  If you are good at soldering surface mount you could replace it.  Did it come with the original 12V fans that were mounted in series?  Or do you need part numbers or something?

Schematic for UM2 circuit board is here:

ULTIMAKER 2 SCHEMATIC - click "raw":

https://github.com/Ultimaker/Ultimaker2/blob/master/1091_Main_board_v2.1.1_%28x1%29/Main%20Board%20V2.1.1.pdf

 

Bought some BC817-40 transistors and 2 pcs 12V fans, will have it next week.

 

Did you check the voltage at the fan pins on the PCB though? The wiring inside the sleeve is not dependable - there are little connectors in there and the wires can easily come loose that go to the fans. So check the voltage at the PCB first.

Voltage on PCB were 0.24V

 

The easiest way to turn the fans on is probably to select PRINT, then select any print then immediately go to TUNE menu and then set fans to 100%. The printer will not start printing until you exit the TUNE menu. I think.

No respond from fans at all. Dead silent.

 

Check this post

https://ultimaker.com/...head-fan-not-working

Test 1: T1 = 0.26

Test 2: T1 = 0.54

Test 3: T1 = 0. 75

Thanks for all the help, will update as soon everything is mounted.

[1-prop-head 1]

Just a bit more on this side fan subject.

After a short circuit caused by me crimping one of the side fan wires between the aluminum housing and the lower plastic nozzle housing I smoked the wire to one of side fans.  Testing the fan using an external power supply showed that only the fan wire needed repair and after that the fan worked fine under test.  When installed on the Ultimaker 2 the fans still did not work so I replaced the transistor on the main board with one I purchased from Digikey (BC817 NPN transistor ).  Still failed and finally found that the series bridge wire (green on my unit) was open and needed to be replaced.  As stated above check those wires. 

 

Fans are 12 volt each wired in series so the 24 volt Pulse Code Modulated current source is divided between the two fans. 

 

To test use the Maintenance/Advanced/Set Fan Speed option which will let you run the PCM controlled circuit from full on to off easily.  I am pretty sure I did not need to change the NPN transistor on the Main Board but I am not going to put the old one back on the board.