Precision 7910 iDRAC not responding

Hi Friends,

                  We have got a HDD fault on our DELL P7910 and tried to fix it with new HDD. When we start the machine, it shows initializing iDRAC... and finally a message with iDRAC not responding. I ve tried the method suggested by DELL while booting but it doesnt worked. This workstation somehow running but the noise of fans are huge and the blue LED in front is on. I dont know what does it mean. Can anyone advise ?