Filament broke
Hey guys I have a problem and I can't fix it. Maybe someone of you has an idea. I have my mk4 for 1 week and I can't believe that I have to buy me a new nozzle every time that happens. 
RE: Filament broke
Hello Perrito
I've no solution but exactly the same issue. After about 12h overall print time it happened. Looks exactly like on the picture above. Hope that there is a solution to get the filament out and a general fix for this problem.
RE: Filament broke
I had this problem once and here is the post about what I did then: https://forum.prusa3d.com/forum/postid/655134/
Probably not.
Take care not to touch anything hot:
Open the nextruder and heat the hozzle to printing temperature, take a 20cm of filament, cut the end at 90° - then, bypassing the drive gear, use it to push the broken filament through the nozzle. When you are sure it's the length in hand that's extruding, pull it out sharply.
The only time I've seen filament broken at the nextruder it was damp ... another reason to dry it.
Cheerio,
RE: Filament broke
Thanks for the provided solutions to remove the broken filament. I'll try them out soon.
I used the original Prusa PLA and I just took it out of the sealed bag so I must assume that it was factory dry
Never assume new filament is dry.
The worst thing that many people do is load filament and print something, leave the printer loaded overnight to print again in the morning - then complain about a sudden loss of print quality.
Cheerio,
RE: Filament broke
This is my solution for keeping filament dry...
RE: Filament broke
Thanks for all the suggestions. I'll stop here. I do have the impression that the filament got stuck inside the tube and not in the nozzle. After heating the nozzle I was able to put the included needle in without resistance. Next time it happens I'll directly contact the official support.