Hi There
Many thanks for Help, i found the issue, i go first to the Dealer and the dm820hs was starting without any problems in his area. I go back home connect the dm820hd back to the TV and Network the issue is still there. After them i power off the dm820hd disconnect the HDMI Cable and start it again, the dm820hd starting without any Problems. Now i change the HDMI Cable and use that was delivered with the dm820hd and the dm820hd starts without any Problems. I test the other cable with an AppleTV4 and another TV, the HDM Cable is Ok, both Devices are working perfect.
Regards obraendl