Hi.

I have been fighting with my new Sapphire HD 3850 AGP the whole day and I am still no wiser. After reading posts on tehis forum and other places I was pretty certain my Antec Phantom 350 would power the card. After all in had no problems with my old XFX 6800GT. But it does not.

Ati recommends large power supplies rated around 600watts. This is their recommended list http://ati.amd.com/products/certif [...] plies.html

Worst case scenario I anticapted was that it would boot and be unstable or halt and display an error message. But I have tried a few thing and NOTHING happends. It is as if had had not even connected the power cables. At best my CPU fans spins one revolution.

Is this a sure sign of underpower or a sign of a faulty card?

I would like some input before I go ahead and invest another 150 bucks into this old machine.

If you wonder about the rest of the machine. It is 2 harddrives SATA, CPU (Intel duo quadcore 2400mhz), 2 GB ram, a soundcard and not much more.

you only have 350W, you definately need 450-550W. 600 to be absolutely safe. Quad core CPUs are very power hundgry. You will need a new power supply. Those damn pre-built computer leave no room fro expansion.

Antec Phantom units are not meant for powering demanding computers, they are meant for extremely silent operation (Phantom units are passively cooled PSUs). You should definitely look for a more powerful unit that suits your needs.

I know it is underpowered, but is it normal behaviour for an underpowered system to act as if I have not turned the power on? Shouldn't there be beep och some sign of life? Want to make sure before buying a new big power supply.