If the error appear after power on during startup you must check the behavior of the print head .
1. No movement in the motor during autotest: this can be due to no power on the motor, motor damaged or mechanically blocked or no tension on the head drive cable.2. Motor is moving “shakes” to the left, this means that plotter cannot recognize the position of the print head, is not reading properly the encoder strip, check CON8, encoder strip, print head electronic board or master board.
If the error appear during printing can be due:
- low tension on the head drive cable ,
- oil on it or motor pulley not well tight ,
- damage on encoder strip ( you can check it through the encoder strip test)
- failure on the motor, ( test with new one )
I suggest to remove the tensioning plate and check if is not bent.
If all above are checked and OK most probably you need new motor.
I suggest you to contact GT representative as they have spare parts and can quickly fix your plotter.