Fans always on

[cora111 0]

Hi,

I'm observing a new problem of my Ultimaker: The fans are always on. They start instantly with switching on the machine.

I can't alter their rpm any more with the UltiController nor I can't change the speed with Cura. Even when I put "M106 S0" via Cura's command line, the fans don't respond. They're staying on.

I have absolutely no clue what's causing that. Can someone help me please?

 

[joergen 2]

You mean the hot end fan? if that is always in, check the wiring, if it is actually plugged into the right port on the board. if it is always on, the darlington transistor PWM'ing the fan is maybe dead, and needs replacement. you can kill the transistor by shortening the leads to the fan.

the main electronics fan under the printer is supposed to be always on.

 

[cora111 0]

Yes, I mean the hot end fan.

I already guessed I killed something on the pcb by accidentally shortening the leads. *blush*

I want to replace the broken part. Can you help me?

Where do I find the part (transistor) on the board?

And what type of transistor do I need?

Thank you!

 

[cora111 0]

*Push*

 

[joergen 2]

http://wiki.ultimaker.com/File:Circuit_complete.jpg

The darlington transistor is the one in the lower center of the image above, right to the right of the three stepper drivers for XYZ. the transistor is a flat part, with 3 legs. de-solder it, and order the same part number at digikey.com or similar dealers.