When flashing IPMI firmware 1.07 -> 1.23 through web browser (firefox 26) there was no progress. It stayed at 0% for several hours. The IPMI Firmware Revision status in BIOS is now "Not working". And LE5 led on motherboard is not lit up.
The following error is received while trying to update firmware to SMT_X10_123.bin with AdUpdate.exe through DOS7.1:
"Fail:w1 inbyte = 255
ERROR:SEND "GetFWUpdateInfo" COMMAND TO BMC FAILED
REBOOTING THE BMC ...
Fail:w1 inbyte = 255
Execute Cold Reset Fail"
Seems like the BMC is unable to reply or reboot. CMOS was cleared and power was unplugged for 30 min and still no change.