Part cooling fan always active - also when preheating

Hi All,

Could somebody tell me how I could fix my part cooling fan?
It’s always running, not only when printing but also when preheating. If I do a print with ABS when in S3D my cooling fan etc are disabled it’s also still running.

At the moment I can only print ABS if I unplug the part cooling fan from the printhead mobo.

Thanks for your suggestions!


Can you try using Repetier-Host rather than S3D? Can you use the fan slider to control the fan speed from the Manual Control tab? Either that or try sending M106 S255 to switch fan fully on or M107 to switch it off? If that doesn’t work, then it suggests a hardware fault with your board (see - chances are its a buggered diode or something nice and simple? If M107 command does work, then maybe there’s a config issue with S3D?

What was the last thing to change since the fan last worked correctly?

You can control the fan in S3D. Maybe your setting is to have to fan working during all phases…

Have you tried swapping Fan 1 and Fan 2? Mine used to be always blowing. Then I swap fan 1 and Fan 2 on the motherboard. Now, I can adjust the cooling fan speed on control settings.