1.) Turn on the power switch of DM520 / DM525 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 / DM525 is in Rescue Mode
5.) You have to enter via browser -> "http://dm520" (without "" ) or IP-Adress of DM520 / DM525 which is shown on TV
6.) You will see Rescue Mode of DM520 / DM525. Click "Firmware upload"
7.) Now click "Select File" and then choose image for the DM520 / DM525 and after that click "Select"
8.) Next you have to click "Go!" and DM520 / DM525 starts with flashing
9.) After flashing click on "Click here to reboot" and wait until DM520 / DM525 is rebooting