First, try with only one processor and no memory - make sure you get three beeps.
If you do, try one processor and one DIMM.
If you don't, check to make sure the processor is listed at http://www.intel.com/support/motherboards/server/s2600co/sb/CS-033242.htm
Thanks for your answer...
One CPU, no DIMM - I get three beeps
One CPU, one DIMM - runs until POST code 9Ah and the POST jumps to 0Dh (no beeps)