Two things to check:
1. Support of registered memory on S3420GPV was added in BIOS 43. If your board has BIOS earlier than 43, you may need to boot the system with unbuffered memory and update the BIOS first.
2. Note the last letter "i" for Kingston DIMMs in the memory list - it indicates validated on Intel boards. We have seen issues with non-"i" DIMMs on Intel motherboards, although memory specs might be the same.
From "Intel Server Board S3420GP Technical Product Specification"
S3420GP has the following limitations:
- 256 Mb technology, x4 DRAM on UDIMM, and quad rank UDIMM are NOT supported
- 256 Mb/512 Mb technology, x4 and x16 DRAMs on RDIMM are NOT supported
4GB 512M x 72-Bit PC3-10600 CL9 Registered w/Parity 240-Pin DIMM
This document describes ValueRAM's 512M x 72-bit 4GB (4096MB) DDR3-1333 CL9 SDRAM (Synchronous DRAM) registered w/parity, dual-rank memory module, based on thirty-six 256M x 4-bit DDR3-1333 FBGA components.
I think this is the problem: the S3420GP(V) does not support x4 DIMM's.
I encountered the same problem, difference being the memory model used by me (KVR1066D3S4R7S/2GI 2GB 256M x 72-Bit PC3-8500 CL7 Registered w/Parity 240-Pin DIMM - based on eighteen 256M x 4-bit DDR3-1066 FBGA components - also in the tested list).
On the Kingston memory configurator results are as follows:
ValueRam Server Premier Memory: Guaranteed Compatible- KVR1333D3E9S/2GEF 2GB 1333MHz DDR3 ECC CL9 DIMM w/TS Server Elpida F- KVR1333D3E9S/4GEC 4GB 1333MHz DDR3 ECC CL9 DIMM w/ TS Server Elpida C- KVR1333D3E9S/4GHB 4GB 1333MHz DDR3 ECC CL9 DIMM w/ TS Server Hynix B(all based on x 8-bit DDR3 FBGA components)At least until now i didn't see that this serverboard (S3420GPV) works with DIMM's used by me (based on x 4-bit DDR3 FBGA components).