Dear all,
I got this problem for about half years, but I can't fix this problem.
My adapter has some noise when my UM2 is running, then my extruder motor fail to turn a full circle.
First I thought that is my extruder sucks, so the motor can't push the PLA to the extruder. I replace a new extruder for my machine, but I still get this problem.
Then I hear my adapter has some noise, so I think there is not enough power to heat the extruder constantly and the temperature is less then the melting point for PLA, such that the extruder motor can't push the PLA to the extruder.
When the adapter get louder, the printing quality will get lower. Here is my adapter sound and extruder motor video.
Adapter: http://youtu.be/9CS5L8Mr4cY
Extruder: http://youtu.be/X7NM381hLOE
Printing: http://postimg.org/image/ncu0t5l3x/
The tension of my extruder is not the problem, because I have try tight and loose tension.