Problem with stepper motor for extruder2

The printing head with the first extruder ist working properly but the stepper motor for extruder 2 (add on K8402) is not - the loading of the filament is not working.

The motor for the left filament (ext2) is rotating in both directions rapidly, slow at the beginning, rapidly after a few seconds when loading the filament, even if the motor is not built in and rotating free.
I have installed the firmware V1.1 dual head and have done “load failsafe”.

To shorten the posibilities of failures i have done the following.
1.: I flipped the motor driver ext1<->ext2: the ext2 motor is still not working properly. ext1 ist still working. Both have the voltage at 0.9V
2.: I used the cable from Ext2 for Ext1 ->: Now Ext1 has the same effect and is not working properly anymore

One thing i was wondering: In the menu under “move axis” is only ext1 listed: Is this normal?

I think after testing, that the motor is ok and the motor driver too. Also the output seems to be trimmed at the right voltage.

What else can I try? How can I verify that the motherboard is ok or the firmware is working properly?

I have to ask.
You know that the driver card for ext2 mounts 180 degrees from the others right?

Can you post a video of the motor behavior?

the driver card is rotated 180°

i made a video at “loading filament”. i have dismounted most of the casing for better viewing.

youtube.com/watch?v=gjlijx0IYS8

i hope the video quality is sufficent.

When you loaded the firmware did you use the Arduino software version 1.0.6?
You can find it here.
http://arduino.cc/download.php?f=/arduino-1.0.6-windows.exe

In my opinion it seems like the motor is only driven with one phase, the symptoms are: noisy, no strength, no clear direction (turns when it wants).

This is either due to a bad driver module, a bad motor, or a problem with wiring.

You can measure the motor and wires quite easily (ohms) and these are ok then you have a bad driver module.

If you do you can open a support ticker on: http://http://support.velleman.eu/

Thank you the hint with the missing phase. It solved the issue.

The plug for the etx2 cable at the motherboard was the problem. The orange cable was not proberly fixed in the plug so the connection was unstable or even missing.

The motor is now working properly.

No problem.