Gen7 extruder output problem

Hello everyone,
I just recently finished building my prusa together, and are now stuck getting to run it smoothly.
Shortly what I am using:
- Gen7 v1.5 board (etched and soldered by myself, probably should have ordered it from Traumflug )
- Stepsticks bought from ebay
- Atmega1284P
- Teacup firmware and arduino ide to programm the microcontroller
- pronterface to send commands to the reprap

The problem is only the output for the extruder. When i connect one of the motors to it, it will behave in a strange way. It will move only very little in a jitterish way. It is hard to explain what it does, noisy, slow and for a long time, kindof as something would be stuck. It moves though in only one direction, way too slow and not smooth at all (both with and without microstepping, also adjusting the poti on the driver does not help).

I already tried various things for debugging:
- connecting different motors to the extruder output (all motors work fine on other outputs)
- interchanging the stepperdrivers (they all work fine on other positions)
- checked soldering mistakes with multimeter, also exchanged the two 0.1uF capacitors for the extruder because I couldnt check it with the multimeter
- played with firmware-parameters

Apart from that, everything works very nicely. I can controll all the other motors perfectly, can adjust the temp of the heated bed and extruder, and also have reasonable temp. readouts.
Just this extruder output...
I have no idea where the problem could be. Maybe somebody else encountered a similar problem. Does it more look like a hardware or a software problem?

I appreciate every advice.

Best,
Felix

Seen from the electronics side, the extruder stepper is exactly like the X, Y and Z stepper. So I'd plug E into X and try to move that. This should give you a hint on mechanical problems. Then plug X motor into the E socket and watch wether you can move E. You get the idea?

Don't forget to turn off 12V before unplugging a motor or a Pololu. Else your Pololus are at risk.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Hey Traumflug,
Thanks for the response. That is already very good to know, that electronically the extruder is the same as the other motors.

For everyone interested, I uploaded a video to youtube: Faulty Extruder-Output
There, I connected my extruder-output to the x-axis-stepper. So, one can easier see the behaviour (in the beginning I let the y-axis run, which is very smooth).

Now, I will check again the board, and play a little bit around with the firmware. I hope I can find the mistake, otherwise I will check next weekend again.

Best,
Felix

Motor current is apparently way too high: [reprap.org]

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

I also adjusted the drive current. It didn't make a change.
After a couple of hours trying, I changed to Marlin Firmware, with which it runs fine now.
It is a real pitty though, I really liked the neat and intuitive programming of Teacup.

Thanks for your advice Traumflug, and keep up your great work!