Computer won't boot....sometimes

[Serrith]

Hi everyone, let me start off with informing you that I am not a complete idiot when it comes to computers, so any help you can give would be greatly appreciated. I have been trying to get my wife's computer to run stable for a couple weeks and I just can't get it right I feel. The system is below:

Mobo: Asus A8N32-SLI Deluxe
Processor: AMD Athlon X2 3800+
Ram: 2 1g sticks of Kingston PC2700 DDR 333Mhz
Graphics Card: Nvidia 5800
Power Supply: Antec 500w

So anyway, I wanted to update my wife's computer to 2g's of ram. And the processor says it supports the ram I purchased. I installed it and...it wouldn't even boot up. So naturally I figure it's bad ram. Put the old stuff in....still won't boot up. Well I decided to take a break, came back 20 mins later, and it booted right up! I didn't do anything in that time. So I decide to give the new ram a go again. I switched it out, and it wouldn't boot up again...so I reset the CMOS settings. Turned it on, and viola, it booted up. Set up the BIOS, and figured I had fixed the problem. Woke up the next day...and the computer wouldn't boot again. Reset the CMOS again...nothing, no boot. Waited 20 mins...and look at that, it booted up again! So my problem is, sometimes the computer boots, and sometimes it doesn't. Temps run fine, so its not overheating. I am fairly sure it has to be a BIOS problem of some sort, I am not very good with Ram timings, so it could be there. I just have no idea, especially cause it didn't boot right back up with the old Ram in either, yet this problem just came to be with the installation of the new ram. Anyway, any help you might have would be great. Thanks.

Nathan

[liljim]

i think most of your problem is with the 333 mhz ram, you need 400mhz in that machine or you will have to underclock the cpu for stability. I dont know if its a glitch with asus or if its a general issue but for example, with my own asus board i cant seperate the cpu fsb from the ram fsb. If your running your cpu at 400mhz(where it should be) your running your memory at 400mhz also which is obviously overclocking it. You can set the memory speed in bios to SPD but it will still base off of the cpu. If you want to do a test, go into bios and set the cpu down to 333 and see if the machine boots as it should. If it doesnt then the problem is elsewhere, if it does you will need ddr400 ram.