According to the C240 install guide, the problem may be a corrupt Bios BootBlock.
It lists two possible recovery procedures.
Here is the link:
http://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/c/hw/C240/install/C240/install.html#wp1413451
Procedure 1: Reboot With recovery.cap File
or
Procedure 2: Use Recovery Jumper and recovery.cap File
Depending on which stage the BIOS becomes corrupted, you might see different behavior.
- If the BIOS BootBlock is corrupted, you might see the system get stuck on the following message:
Initializing and configuring memory/hardware