Does the System Event Log report anything @www.rcjoshi2011 that might give a clue? (View the event log from the BMC, or you can do ipmitool sel elist with the BMC user/pass/IP/etc. from another Linux machine.)
If you have a support contract still, this is exactly the thing that NVIDIA Enterprise Support can help with - follow the steps in About the DGX User Forum / Note: this is not NVIDIA Enterprise Support to create a case.
ScottE