Computer Building Problem

[WingedWombat]

I'm in the process of building a new computer and I'm having some trouble getting the system to boot up. I have everything connected properly, but the computer only starts up for a few seconds and shuts off immediately. I've determined that all of the parts are in working order, so I don't know what could be wrong. Anybody have any ideas? System specs are:
Soyo KT-880 Dragon 2 Motherboard
AMD Athlon XP 3200+ Processor
MSI RX-9800 Pro 128 MB Video Card
Seagate 200 GB Ultra ATA Internal Hard Drive
Demon Silver Chrome 480 Watt ATX Switching Power Supply
AMD Approved Processor Fan

Thanks.

 

[4W4K3]

sounds like a bad powersupply, or possibly overloaded. what kind of PSU u have and how big is it? also you're sure you have the jumpers set correctly? double-checking never hurts...or triple-checking in my case lmao.

 

[kof2000]

or u can unplug devices one by one.

 

[da_ezman]

480 Watt P/S should be plenty for almost any computer. Good advise to unhook everything except H/D and see if it posts then. Do you get the post beep or beeps? Does it beep before shutting down or just give a splash screen and shut down?
Also check the voltage selector on the power supply. Make sure it's not 220v or other weird setting.

 

[Praetor]

480W doesnt mean anything if you've got say 2HDDs and a vidcard sitting on a single rail -- spread them out!

 

[4W4K3]

480W doesnt mean anything if you've got say 2HDDs and a vidcard sitting on a single rail -- spread them out!

OOO QUESTION! how do you know if you've spread your hardware evenly across the rails. i know each part only runs on a specific rail...but yoiu said "spread them out"...how would u do that? i jsut pug into molex randomly...never thought of spreading power usage out.

 

[guitarian]

i recommend taking all the pieces out and resetting the bios via the motherboard's jumper (if you don't know how to do that, consult your motherboard manual. it'll be under resetting cmos, etc). throw all the pieces back in and be sure they're properly situated and retry. as mundane as this task seems, it has really helped with the akward starts i've experienced while building systems.