Using a 7inch hdmi touch display on raspberry pi 2 with openhabian

Hi folks,

I want to use a hdmi display with my raspberry pi with openhabian. I bought this display:

I changed the configuration in the /boot/config.txt as suggested by the manufacturer

hdmi_cvt=1024 600 60 3 0 0 0

But nothing is showed on the 7inch display.

To ensure that the 7inch display works correctly I used an another raspberry pi with jessi image connected over HDMI to the 7inch display and it works fine.I also used my laptop connected to the 7inch and it workss too.

After that I changed the power supply to 5V/3A for the raspberry pi wit openhabian. Same issue, display not works.

But when I’m using a normal TV with HDMI possibitly connected to the Pi with openhabian It works.

Only the combination of Pi with openhabian and 7inch display doesn’t work.

Whats the problem, can someone help me out here?