# Specific 3D Printers, Scanners, & Hardware > Other 3D Printers / Scanners / Hardware >  FLSUN Prusa i3 Z axis problem after installing Marlin

## Spisme

Good day!

*WARNING bad english ahead, it's not my native language*

I've just got a new 3D printer, a FLSUN Prusa i3, and I have some really bad problem with it.

I use Repetier, Arduino, Marlin and an autoleveling sensor

Since I've installer Arduino and Marlin, my *Z axis* won't go down when I press the *Z HOME* or the *MAIN HOME (for X, Y and Z)*.
If I press the* Z HOME*, the hight increass of *2mm* and the *MAIN HOME* increass the hight of* 7mm* then both reset the hight to 0.
If I increass the hight, without pressing the *Z HOME* or *MAIN HOME*, I can lower it with the software.
If I press one of the *HOME* I must lower it manually because *REPETIER* don't allow you to go bellow 0.

Before installing Arduino & Marlin I had no problem except for my LCD screen that I wasn't able to go in and it still not working...
If I was pressing the *MAIN HOME*, every axis was going at *HOME*, the *Z axis* was lowering, touched the plate then going *2mm* higher and the extruder was going in the midle of the plate.

The firmware I had on my sdcard can be found here: https://github.com/vovcacik/Marlin

PLEASE can you help me?

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## Roberts_Clif

can not speak for FLSun Github Firmware. 
However I have Marlin 1.1.x Running. I can see the settings you need for the FLSun I will help you get it running.

https://www.youtube.com/watch?v=Ok7igmasvXQ
I watched these instructions videos And believe I can Help I use Google Translate so if you cannot explain in English Write in your own language and I can translate to English.

Are you End Stops NC or NO (Normally Open or Normally Closed) By what you are saying they maybe setup wrong.
What is you Proximity sensor.

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