Hello

I am currently have a amd athlon 2800 & 400w psu, But i new computer is

AMD 64 AM2 3800+
MSI K9N- NEO
Geforce 6200 le Graphics Card PCI Express
3 x 512mb of DDR2 Hynix Memory
250gig Western Digital sata drive
Nec DVD writer - due to be replaced
Sony CD Rom Drive
Floppy
External 120 gig Usb2 hard drive
BT Total Broadband

Any ideas on what psu i need i was looking at a 600w on ebay but the manual for mobo said 350w is plenty?? ???

Hi brogusblue, welcome to itsallPC

600W PSU is way overkill for a system like that. Maybe with a couple of graphics cards installed, you might be looking toward 550W, maybe 600W depending on the manufacturer. A single core CPU and entry level graphics card will not consume much power. 400W will most probably be sufficient, however, it might be a good idea to read this post.

I've seen a lot of disparity between 400W PSUs. Some are total rubbish, not even sufficient to power a digital wrist watch. Check the label for the amps supplied on each of the +12, +5 and +3.3 Volt rails. Another good indicator is weight. The more power it supplies, the hotter it gets and therefore the more cooling it requires. The more metal in the cooling heat sinks, the heavier it is. Unfortunately you need to have handled quite a few PSUs before you can judge them by weight.