problem with sanguinololu

It was working and now my extruder stopped working.

I connected my extruder stepper motor to z axis and it turns. This means the extruder stepper motor is working
I then swap out the z axis and extruder stepsticks (ramps).
I connect my extruder stepper motor back to extruder connector. motor does not rotate?
I know that the stepper motor and ramps are working. What can I check on the main board?
Any sugestion?

Step, enable and direction lines go directly from the micro to the stepsticks, cct

Probabbly Time to replace the 644p/1284p

But check the soldereing on Pins 1,2 and 20 on the main chip. (top left of cpu chip is 20, top right is 2 and 1)


Also check all the soldering on the Extruder pololu socket

Edited 2 time(s). Last edit at 07/21/2015 05:06AM by Dust.

Hello everybody,
I know this thread is a little older, but since yesterday I have the same problem: extruders stepper won´t turn anymore.
I connected the extruder stepper to x,y, and z axis and the stepper moves. but not on its own place...
I swapped the pololus, all four are working,
@Dshiri1: did you solve the problem?
Regards
Rollo

Is the temperature above the safe limit in firmware?