I am also having the same problem. I purchased some ECC Registered memory on eBay. It was actually Dell brand too. 400MHZ, PC2-3200, all that jazz. I have the SC420. When I installed the RAM, I got 4 beeps, and no video display. Is there something you have to do in the BIOS to get it to recognize the RAM? Or did I get bad ram? Uncompatable RAM?
I know it's registered, because I made the first mistake my bying unregistered ram, and it actually told me I needed registered RAM. I really don't know how I could have found more compatable RAM. So what am I doing wrong?
Here is a link to the eBay auction where I bought the ram:
1 GB DDR2 (wX512 PC2-3200 400MHZ ECC Registered CL3.0
Just in case the link doesn't work, here's the details from the auction:
DELL 1GB (2x512MB) PC2-3200 DDR2 400MHZ ECC Registered CL 3.0 Memory Module
Dell Infineon PART # HYS72T64000HR-5-A
2X512 1Rx8 PC2-3200R-333-11-F0
COMPATIBLE WITH PC2-3200 ECC COMPUTERS
EXCELLENT MEMORY FOR ALL MAJOR BRAND COMPUTERS: DELL, HP, FUJITSU, COMPAQ, ACER, ETC.
ADDING MORE MEMORY IS THE CHEAPEST AND EASIEST WAY TO INCREASE YOUR COMPUTER PERFORMANCE!
Any help would be appreciated!