1.) Turn on the power switch of DM520 at the back
2.) If LED on the Standby-Button at the front lights up, keep it pressed until LED quickly lights up red and blue
3.) When LED stops blinking then release Standby-Button
4.) After few seconds a info shows up on TV, that DM520 is in Rescue Mode
5.) You have to enter via browser -> "http://dm520" (without "" ) or IP-Adress of DM520 which is shown on TV
6.) You will see Rescue Mode of DM520. Click "Firmware upload"
7.) Now click "Select File" and then choose image for the DM520 and after that click "Select"
8.) Next you have to click "Go!" and DM520 starts with flashing
9.) After flashing click on "Click here to reboot" and wait until DM520 is rebooting