Hi,
Other than RHEL, have you tried installing Windows OS, just to make sure server hardware is working as designed.
BL460c G6 supports the follows RHEL versions:
RHEL 6.0
RHEL 5.3
RHEL 4.8 (Intel Xeon Processor 5600 Series)
RHEL 4.7
Visit this link for RHEL support matrix.
Thank You!
I am a HP employee.