Good evening,
I finished the printer and now I use this part of the user manual : k8200.eu/manual/printing.
001 Chapter OK
002 Chapter
Problem #1: When I press the Z axis up 10 mm button the printer head goes up 10 mm when I press the down button the head goes down, but if I press again the down arrow the head does not move. (The coordinate it was zero). If I press the Z axis home button a head goes up a bit 1-3 mm and after the head cannot go down.
Problem #2: When I press the Y axis any button (back, forward, home) no any reaction. I can move easily the heated bed in this direction. I had pressed the Y home button, the plate is moved back a little bit and after nothing.
The X axis is working well (the home button and the arrows) everything is OK.
Plesae help where can I find the problems.
Thank you very much.
From your description this sounds like an end stop (micro switch) problem for the Y and Z axis.
Unplug the Y and Z end stop from the board and check the resistance.
When the the are away from the end stop you should see a short.
When the are against the end stop you will see an open.
Make sure the wires are on the outside post of the switch.
Thank you. Today afternoon I will check the end switches.
Good evening 
I checked teh end switches and I found a not well soldered wire at the Z axis endswitch, but the another axis endswitch was good.
So, I switched on the printer and I clicked the home buttons, X and Z perfetto, but the Y axis motor steped one or I do not know how many, but it was very small movement and after stopped. After the printer did not react the Y axis command buttons.
Reconnect the printer from the Repetier and no reaction 
and after I pressed the reset button on the panel the Y axix command buttonare still not working. I measured the milivolts on the panels (426, 425, 427, 420).
Where can I search my problem, maybe the wires of the Y axis motor?
But I am happy because two axis is working well :))
I am looking forward your answer.
thank you, thank you.
You should check the wires.
Also set the reference voltage to 0.55 I have found that to work best.
Halleluja,
Thank you very much for your help. I checked the wires and there was a problem, I mixed the wires a bit. Now it is working well.
Thank you again. If yo would like a Handpainted fridgemagnet from Malta. Just tell me and I send to you one. You can see www.luzzufaces.com.mt. 
thank you and have a nice day
Arpadosso
Hi,
Just knowing that I helped with your printer is payment enough.
Happy printing!
and after I pressed the reset button on the panel the Y axix command buttonare still not working. I measured the milivolts on the panels (426, 425, 427, 420).