Erratic movement of laser head.??

[SakokeLd]

gday,
I am having some trouble with my epilog fibre laser. It was half way through printing a job when the head started moving erraticly from side to side along the x axis while still printing but it was also moving slightly up and down on the y axis also. so i pannicked and switched the laser off at the power. I left it a few minutes with the cord unplugged, then tried switching it back on. While trying to "home" itself, it shuddered side to side almost like its skipping on the belt, but then it settled for a moment in the home position, but a second later the laser head shot to the far right, really quickly and slammed into the wall/stop. I switched it off and triad again but it was doing a simmilar thing.
It moves freely along both axis when power is switched off, and i cant see any dammage to belts or wheels or teeth ect. but im not sure what the problem is.
I thought I would post up here looking for possibile solutions before getting a technition to have a look.
Has any one had a similar problem or have any ideas what to check?
Thanks guys
Jesse

[SakokeLd]

Ok so I have swapped the circuit board(head board) on the x axis with one from another epilog laser, but this didnt fix the problem. I have been suggested it could be the flex cord also but not that either. the x axis motor was also suggested but this seems to be functioning.
The thing is, that it shudders along the x axis, and will zoom from one side to the other.
But it also zooms irraticly along the y axis?
I wiped down the sensors im aware of (circuit board sensor and magnets x and y axis, circuit board sensor and wire mesh plastic track x axis) but still has problem.
Im not sure why it would play up along both axis?
Is there a specific part controlling the where abouts of the head along both axis?
Is there other troubleshooting techniques that could help me. Maybe other things it could be (program/virus, circuit board, sensors, motors??)
thanks
Sakokeld