I could use some help with a couple of problems, the first is that my computer is turning itself off (it just loses power as if you had unplugged it) roughly once per day. The other problem, which may be linked, is that when I install 1 stick of RAM the computer works, but when I put two in I get errors on the boot up and Windows won't load. Both sticks off RAM work on their own. The problems started when my PSU shorted out and killed my motherboard (and probably damaged other components). I bought a new PSU and motherboard and also repaired my Win XP instillation since my Hard Drive had picked up some errors in the process. After that the power offs started. I bought some new RAM to see if that was causing the power offs but it didn't help, this is also when I found the two RAM sticks problem. So in short: What could cause a computer to work with 1 stick of RAM but not 2 (I tried using different DIMM slots since my mother board can have the RAM in any combination in them but it didn't help) is it just the motherboard or could the CPU or other component cause it? Could the RAM problem be related to what is causing the power offs (e.g. could the CPU be damaged and causing the RAM issue as well as power offs) and what would people suggest I try next to fix the power offs, buying a new CPU or Hard Drive? Any help would be greatly appreciated! Many thanks, John 648F Neo-L AMI Version 07.00T (date: 07/03/02) Intel Pentium 4, 2.26 Crucial PC2100 DDR-DIMM 512MB CL2.5 Generic Memory 184-P DDR-DIMM PC2100 512MB DDR CL2 MSI AGP GeForce4 Ti4400 Thermaltake Purepower 460W PSU ATX12v 2.0 (+3.3V, 30A : +5V, 30A : +12V, 15A : +12V, 15A : -12V, 0.3A : +5VSB, 2.0A) Maxtor DiamondMax Plus 9 160GB (IDE 1) Plextor CD recorder IDE 40x/12x/40x (IDE 2) DVD drive, not sure what make Win XP Professional, SP 2

If you get post then the cpu is ok. CPU's are either dead or alive in my expeirience . Could be the 2 sticks of memory are incompatable with each other

a random power off is usually caused by an overheated CPU or a faulty PSU. as far as your RAM chips are concerned, one is CL2.5 and the other is CL2, you should get matched chips also... why are you only running pc2100? your processor runs at 800MHz FSB (200MHz actual bus speed), with pc2100 it can only run at 133MHz when it should be running at 200MHz, with pc2100 in there, you are severly bottlenecking your entire system Don't put a question here.

Thanks for the replies! I forgot to say in my first post that the two memory sticks I have been trying are identical: KingMax PC2700 SuperRam 333mhz 512mb ddr oem. I've done some more tests, first I tried both sticks on their own, they both worked. Then I tried them both together, windows didn't load (blue screen of death), then both together with the cas set to 2.5 in the bios, the same thing happened. I also tried installing a single stick in the second DIMM slot to see if that was faulty, but it works fine. The RAM I have in my spec list was what I was using before the PSU fried, it worked fine but when I installed the new motherboard one stopped working (or so I thought), but I am starting to think it was fine but it was just this error with the computer not working with more then one ram stick. I think I have ruled out the RAM being faulty since I have tried all 3 on their own and with each other in various combinations (all work on their own and all combinations fail when together). Could this be anything other then the motherboard being faulty? Thanks again! John