extruder fan not cooling

[DavidG]

I've done a couple of prints but never finished any of them because the plastic melts up in to the the extruder motor and doesn't feed throw the nozzle and I've noticed that the fan doesn't run. Any help would be appreciated

[wmar]

Turn the fan on with "M106 S255".
Remove all "M107" lines from your gcode.

http://reprap.org/wiki/G-code#M106:_Fan_On
http://reprap.org/wiki/G-code#M107:_Fan_Off

I don't know if you're facing a similar issue, but this happened to me on larger prints for slic3r, since the layer takes long enough to print that it should cool before starting the next, so it doesn't turn on the fan. You can change settings in slic3r to always have fan on in expert mode.

[Planwright]

Make sure the fan is cooling in the right direction. With the machine running, use your hand to feel if there is coolness blowing on it. If so, turn it around so that it faces the extruder.

[Planwright]

If the fan does not run, try plugging it into the middle socket. Even though the instruction say to use the outside socket, It did not work, but the middle one did.

[DavidG]

I've tried all those suggestions but still no good I've even bought a replacement fan and it still doesn't work.

[TonyUFN]

I went through the same issues for a short while after building mine.
I saw print failures left and right and started cussing over the extruder design. But then I noticed the fan would not start at all.
What I started to notice was that the fan just simply would not spin up. With some help maybe, but it would eventually quit mid-print.

I ended up replacing my fan with a new one and it(the fan) has been running fine ever since.

Since you have already replaced yours, I cannot help any further other than to suggest you trace your connections all the way back to the mainboard.