Feeding Motor goes forward and Backward

[aenengl]

Hy,
My Setup is a Geeetech I3 ProC with no additional upgrades, Software is Repetier-Host V2.1.2 with Slic3r as slicing program.


i got an Issue with one of my Feeders:
I killed a print and wanted to restart it, since then the feeding motor feeds like 1mm, then rolls back 1mm. (second Extruder has no issues) I Had no issues before and changed nothing between the two Prints.
Here is what I tried:
1. Cleaning of the nozzle (no problem with feeding by hand)
2. Resetting the Printer
3. Restarting PC and Repetier host
4. Controlling the Feed directly from the Printer: same problem
5. changing of stepper Motor Controller with second Extruder: no change (second Extruder has no issues)
6. swapping the Extruder cables: Issue was now on the second Extruder
7. Loading new firmware on the Printer: no Change

Hope you can Help me

[Gingko]

6. swapping the Extruder cables: Issue was now on the second Extruder

So it seems like the problem is caused by bad cables?
Have you tried to swap the motor with the second extruder?

When the spring has not enough press, the filament might slip when it passes through the screw, I'm wondering if this is similar to your problem