That's ACPI_LOAD_RSDT - clocking on the DIMM slots. Have you tried minimal memory, or a different vendor?
Turns out the memory I was using was DDR2 800, not the DDR2 667 that is required.
BTW where were you able to find that led diag code? Was it in the technical product spec pdf?
Thanks for your reply
Further to this reply, Appendix C (POST Code Diagnostic LED Decoder) seems to be incomplete. Here is a list of additional BIOS codes which can be translated:
Your diagnostic code LED color pattern:
<R G R 0>
translates into these nibbles:
1 0 | 0 1 | 1 0 | 00
put the upper and lower nibbles together and you get A4h
Look at the link for A4h and you'll find description ACPI_LOAD_RSDT.
I had the same problem for S5000PAL