X-Motor faulty output?

[PavelFurie]

Hi all!

Just finished the assembly of the Aluminium Prusa i3 pro A - and I'm having a weird problem that I hope you can help me solve:
The X-Motor - jiggles back and forth every time I try to move the X axis(Repetier) or when auto homing.(See attached YT link)
https://www.youtube.com/watch?v=w7-LK2_eqoQ

I've tested the following scenarios to determine the source of the problem:

* I have replaced the X motor driver with another - and the Motor still stutters.(Although when the same driver and motor are used for Y socket - both work fine)
* I have tried running both motors with a different cables on two different outputs(X motor stutters on X socket, Y Motor stutters on X socket, X motor is fine on Y socket and Y motor is fine on Y socket)
* I have tried to redirect the X motor cable to EX1 in the box - and then connect the x Motor to the EX1 socket on the connector board,(To eliminate a wrong wiring/soldering on the switchboard) problem still there.

So, Motor is fine, Driver is fine, Switch board is fine, Cables are fine.
What's left is the logic board I guess.

Any feedback is appreciated...