Problems with A8N-SLI Premium based machine

[Gunbuster]

I recently I got the chance to buy an Asus A8N-SLI Premium and a Geforce 7800gt (PNY with aftermarket silent cooling) from a friend.
I bought a Coolermaster Elite 330 with a eXtreme Power 460W PSU, an Athlon Socket 939 3500+ CPU and 512mb of DDR ram (Corsair VS512MB400/EU).

I can just get it to boot.

If I have everything just so I have a 1 in 2 to 1 in 5 chance of it posting (ie bios beep). When it does run it will restart it self randomly. I often wont post at all if a CD is in the drive.

I was wondering is it possible the PSU is just not powerful enough for this setup plus a couple of IDE PATA Harddisks and a DVDRW. I have the same problems without them plugged in. When I wipe the bios, it seems to work first time after that, so I checked the memory timings and that seemed to work.

I'm sorry to ask all this, it is supposed to by my sisters new machine to replace an Athlon 850mhz I built back in 2000-2001.

I found all this a bit odd, as my Core 2 duo + 7950GT + 946g mobo runs perfectly fine on a 380watt Seasonic. Is it that the older 7800gt and 3500+ are more thirsty? It is an SLI board so it could just be that 460w ain't enough?

Any help would be greatly appreciated.

[Ciber]

The extreme power psu prolly isn't as capable providing power as the seasonic even though the number is higher, so you could maybe try that PSU with it instead. The fact that it's intermittent suggests a loose connection, so try reseating stuff like ram, cards and check your mobo power connections.

[Gunbuster]

Hmm, I plugged in the extra connector for sli power, even though I only have one card in. It won't cold boot startup, but if I leave it for a minute or so and then quickly switch off then on it will start. It makes me think that it is right on the edge of what the psu can cope with.

[Gunbuster]

I tried my trusty Seasonic, it turns out it's actually a 430watt S12 (not v2). I had the same problems. It wouldn't cold boot, but it would warm boot with a CD in the drive. So a mild improvement.

Is it possible the Coolermaster has damaged the motherboard? or is it more likely the Seasonic was just helping an all ready limping motherboard?

[amjedm]

Have you tried some different RAM?

When I had similar problems with a A8N SLi Premium, it was RAM related, it didn't like Crucial Ballistix.

I removed BIOS battery for 30 mins and just about managed to get one stick of Ballistix tested in one slot. Gave up in the end. I RMA'd the memory and sold the replacement is what I mean.

[Gunbuster]

I'm afraid it's b0rked. I tried the ram that was originally in it. I definatly didn't work in slot 1 and acted exactly the same way in slot 3.

Thanks for the help everyone.

[amjedm]

I'm afraid it's b0rked. I tried the ram that was originally in it. I definatly didn't work in slot 1 and acted exactly the same way in slot 3.

Thanks for the help everyone.

A bit sad that IMO as it was supposed to be your sister's new PC (as you posted above).

I take it slot 2 and 4 are faulty as well?