[Chaosed0]

I have a new gaming build that is turning on and then simply shutting off again almost right away. This means I don't have enough time to install Windows, get into the bios, or, sometimes, even see the motherboard splash screen. Here's my build:

RAM: Patriot Viper 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory
HDD: Western Digital Caviar Black 640GB 3.5" SATA 3.0Gb/s Internal Hard Drive
PSU: PC Power & Cooling Silencer Dell Upgrade PPCS500D 500W Power Supply
Processor: Intel Core 2 Duo E8400 3.0GHz LGA 775 65W Dual-Core Processor
Case: Antec Three Hundred Black Computer Case
Vid Card: SAPPHIRE Radeon HD 4890 100269SR Video Card
Motherboard: GIGABYTE GA-EP43-UD3L ATX Intel Motherboard

Hope you guys can help me with this. I'm fairly new to building systems, so if the problem's obvious, I apologize. Thanks for any help you can give.

 

[Wrench97]

A 500w psu is too small for a HD4890 you need to be in the 750w range like a Corsair 750TX, 850TX or the PC Power & Cooling 750w unit.

check that the heat sink is fastened tightly to the motherboard and that all 4 legs are tight.

 

[Chaosed0]

http://www.guru3d.com/article/radeon-hd-4890-review-test/5

On an average system we feel that a single Radeon 4890 series requires you to have a 550 Watt power supply unit at minimum if you use it in a high-end system, and I feel that's a little on the safe side. Also recommended is a total of 32 AMPs on the +12 volt rails for stable power distribution (in a single card configuration).

D'oh. I guess I'm getting a new PSU.