Aryan2411, I had the same problem as @CODE I followed your instructions to the letter, but I had the same problem upon reboot. To check if the problem was resolved I used the One Flash utility with the -i parameter. It still said Failed to communicate with BMC. I downloaded 3rd party ipmiutil to check the FRUSDR and it read everything correctly, even the BMC version 0.66
I still couldn't access the BMC module, but the front LED was solid green, before it was blinking amber and green, that was my initial reason to flash the FRUSDRs and BMC.
After I gave up out of frustration, I decided to swap RAM from Channel 0 (4 modules all on channel 0) to channel 0 and 1 after removing the AC plug. I booted the server, ran IASC and it was reading the BMC! I am not sure if it is because I powered the AC off or if the RAM swap might've updated the BMC data to identify that the RAM has switched banks and maybe "unblocked" the BMC.
So I would suggest following Aryan2411's tutorial but after flashing both banks removing the AC power cord until the power dissipates, plugging AC back in, wait for the LED to change from flashing green amber to solid green, then trying to launch the IASC after booting up the system again. If that doesn't work unplug the AC cord again, swap RAM, plug AC back in, boot, check IASC.
I can't think, logically, how the RAM swapping could've fixed the problem, so I believe it was the AC power being lost and returned. Either way I am just happy that IASC can communicate with the BMC again! I was beginning to lose all hope!
Thanks Aryan2411
