First check if you have a "Refresh" version of the board. If not you'll need to boot it up with a Xeon 5500 series processor and update to BIOS 45 or later. See http://www.intel.com/support/motherboards/server/sb/CS-031498.htm
Thanks for your response.
I have now purchased a S5520SCR workstation board to replace the defective S5520SC board which never worked from new. With the refresh model can I carry out the initial boot with both L5630 CPU's in place or do I still need to carry out a BIOS configuration using a 5500 series CPU?