sunfire 4100 xbrowser problem

I installed SGD on SUNfire 4100, every thing was working fine, suddenly the machine shutdown due to the power failure. When I again switched it on, it is asking for the login in text mode. No graphics are displaying and even I cannot get its display via xbrowser. While before it was working fine.
Telnet is still working, any help in this regard will be appreciated.

The problem was in the hdd, I replaced it now every thing is o.k, thanks