Geeetech

I bought a GEEETech I3 PRO B from Geeetech-official on ebay, with a GT2560 board and 4 A4988.
I managed to assemble everything in around 9 hours.
At the moment I've got this problem: using manual control from the LCD (PREPARE/MOVE AXIS) i can move X and Y axis, but when I move Z axis only one motor runs. I then inverted the cable and the other motor is activated, so the 2 motors should be ok.
I then tried to invert the drivers on the board, just to see if one of them could be defective, with same results.
Another strange thing is that when I move X or Y axis, I can only go counterclockwise, I mean the display shows 0.00 and i can turn and then come back.
Is that normal?
Please, I need help to understand if it's a board problem or something else.

Are you sure you're running the right firmware?

http://www.geeetech.com/forum/viewtopic ... 20&t=17046

Yes, I installed the right firmaware for I3 Pro B from the Arduino IDE.
Even using Repetier-Host only one Z-axis move.
I actually didn't install PI3B-ramps.rar which should contain the servo firmware. Could that be the problem?

No, it seems Ramps is only necessary for I3 Pro A.
I can only think of a faulty board

Either printer can have either board as far as I know. My I3 A came with a sanguino board, but I have changed it for a GT2560.

You have to select the right firmware for your setup, so choose either one of these matching your board:

GT2560: http://www.geeetech.com/forum/download/file.php?id=2819
RAMPS: http://www.geeetech.com/forum/download/file.php?id=1553
Sanguino: http://www.geeetech.com/forum/download/file.php?id=1554

With reference to Z axis problems I too have a the problem where both Z axis motors are inactive, driver board (A4988) eliminated and a reflash done with no effect. It seems there may be a hardware issue with some of these boards .