Front fan (hot end cooling) does not spin anymore

[DukeofCool72 0]

Hi all - my front fan (UM S3) doesn't spin anymore. I noticed this after starting a print and every time around 10 minutes there is no more extrusion and the filament stuck in the metal tube of the print core (different cores!) because of melting too early.  I already checked the fan (was not broken or blocked) and even replace it with a new one but still it doesn't work. I called my local dealer (UM general import igo3d in Germany) and he insists of shipping the printer to him for a check. It is a hassle because I have to put it back in the factory box (which I don't have anymore), pallet it and ship it to the shop. 

Is there anyone out here who had the same issue and knows what do do? I even would consider to buy a new part although I'm still have full guarantee (printer bought 10 month ago) to avoid to ship it back to the shop.

 

Thanks!