i have R420 and my problem is that fan is full speed and idrac initializing not responding and auto reboot. the problem is start from i upgrade my bios etc and during installation upgrade is stuck (hang), after that this problem accure. i already try nvram reset, telnet using serial (which appear is the same windows with the monitor), using download iso from dell (and hang during collecting system inventory or something like that), download all tools that i can find on dell.com. any idea what should i do anymore ? sorry with my bad english. thank you albert dalton