Geeetech

"the board GT2560 does not work can not install the firmware for days ."
Does it show any error info?

I think you might need to check the PTFE tube according to this link:
http://www.geeetech.com/forum/viewtopic ... 19&t=17616
And the Z axis, check the driver voltage here, maybe too low:
http://www.geeetech.com/forum/viewtopic ... 17&t=17038

retraction length too big, usually 3-4mm is enough, and speed 40-50 is fine. I have a config settings for you here, see if it helps:

Seems like a defective motor, if you plug this motor to the X axis and it still behaves like this, then it might be dead. And have you checked the motor cable? Sometimes a dead cable will cause this problem too. you can swap it with the other cables to check it.

you can find the one for your I3X on the first page of this post, right after the firmware for the I3 M201.

1. the baud rate for this printer is 250000, you can check the user manual to set up the printer.
2. Regard to question 2and 3, I think maybe the slic3r settings of your printer are not proper, you can use my settings here:

the SW is correct, I can use it without problems. Maybe swap the extruder driver board with the X axis one, see if the driver board is dead or not.

If works fine under manual control then it should be working when actual printing....The firmware, you can try this one here:
http://www.geeetech.com/forum/viewtopic ... 20&t=17046

then use the working driver board on the extruder to verify the other driver boards, replace them one by one with the working driver, see if those motors will working or not.

yes you can, I didn't use them too. But the truth is, the little fan on the hotend is used for cooling down the tube, not for the nozzle/filament when printing, so no need to control it too. And though it only has two wires, it can be controlled by the PWM fan connector too, cause it only use the + ...