Hi...i am a new user here. In my case my HS-DH500GL ran into EM mode a few days ago, most likely because of a lost power. I tried to upgrade the firmware. After the upgrade and reboot, the error light will keep blinking. I once waited for half an hour and it's still blinking. And I couldn't access the web interface. After reboot it several times, it went to EM mode again. I managed to telnet to it.