Fan Problem with Prusa I3

Hello,
I bought a new Prusa I3 Printer Kit from Gear Best (http://www.gearbest.com/3d-printers-3d-printer-kits/pp_364451.html). First I updated the Firmware to Marlin 1.0.2-2. Everything works fine excepted the extruder Fan. The Problem: As soon as I plug in the printer to the power supply the fan starts spinning 100% and I can’t stop in via the “Repetier software 1.6.1”. I’m able to adjust all other settings via Repetier but the Fan-speed option doesn’t have any influence on the Printer even if the extruder is cold.
Does anybody have an idea what the problem is?
Thanks a lot in advance!
Tobi

What controller board are you using?
What pins is the fan connected too.
Normally the extruder cooing fan is running all the time to keep the filament from getting soft in the extruder throat tube.

Hello,

It's a Gen 2Z V1.2 Board and the fan in connected to Pin 1/2 next to the reset button (look at the picture)

So maybe its normal you think. The printer does only have one fan, on the most videos I found the Prusa I3 have 2 fans is that a problem as well?

Thanks for your help!

according to this mostly Chinese pdf [github.com]

Those pins are just always on 12 or 24 volt.

This would make sense as you should never turn off the fan that blows across your hot end cooling fins

Now if you want an additional cooling fan that software can control plug that into the D9 port.

Thanks!

I thought, the fan should start after the hot end temperature is higher than 50°C. At least it is like that for the makerbot Gen 2 I know.
I will figure that out.

Quote
Tobias85
Thanks!

I thought, the fan should start after the hot end temperature is higher than 50°C. At least it is like that for the makerbot Gen 2 I know.
I will figure that out.

Depends, I know mine is configured to be controlled via pwm but I have seen configs that have the driver electronics and extruder fan permanently connected to supply but these are mostly duel hotend machines.