Extruder not rotating: how can a find out the root-cause?

Hi,
I have a RepRap with a Ramps1.4 shield on a SainSmart2056. I flashed the SainSmart2056 with the latest RepetierHost firmware and use on my Computer RepetierHost Vers. 0.95.

With the manual control funcationality of RepethierHost I checked everything: x-/y-/z-steppers are all fine. Temperature sensors and heating also work.

What is not working: the stepper for the extruder is not reacting at all. Also the driver is not buzzing or getting warm. For me it looks like the driver is not getting any signals.
I already checked the stepper and the driver on a small, separate breadboard and both are o.k.

Since the Ramps1.4 shield and the SainSmart2056 are brand-new (just unpacked), I cannot imagine that the hardware is broken ... but how can I be sure?

Okay, my assumption is the configure.h respectively the EEPROM settings may not be right - but how can I be sure?
I remember, that e.g. a too fast speed in the setting could results on no stepper-reaction at all (but the driver would get warm or make some strange sounds). Anyhow, to make sure it's the EEPROM configuration, can anybody suggest a minimum EEPROM setting for the extruder-stepper which at least should result in any kind of reaction?
Or does anybody know a g-code command, which I could use to check, that the manual control from RepetierHost is the problem?

I would be very glad, if somebody could help me to narrow down if my hardware or my settings are wrong?

Edited 1 time(s). Last edit at 11/07/2014 02:53PM by BigMan200.

Extruder will not run if hotend is not above a minimum temperature.
To test with no filament in extruder send command M302 which is "Allow cold extrudes"
Then try to extrude. Motor should now move.

What should I say: I already tried for hours playing around with the EEPROM and flashed 1000 times with modified configuration.h
But, indeed, the problem was I didn't heat up the extruder while I tried to rotate it.

@george4657: Really, I am very very gratefull for your support. I always appreciate if people like you are helping through a forum other people they even do not know. Wonderful.


Thank you!

You can also run M302 command in pronterface and it will allow you to do a cold extrusion