Had this issue on a new out of the box server. The server was hardware assembled, processor fitted. Then when I powered it on, I received the following error.
Action:Pwer cycle the system. If this does not work then reseat the processor.
If the issue persists, contact HP
As seen below.
As the server was dual CPU, I swapped the CPUs between the CPU sockets, the problem did not follow the CPU, it stayed with the socket. On closer inspection of the socket I could see 1 single pin that must of been damaged during the manefacture process. See below.
After a quick call to HP support on 0845 161 00 50 the main board was swapped out and the issue resolved