Hi guys, I've just finished building my new rig with the following specs

CPU: C2D E6750 2.66Ghz
Mobo: Gigabyte P35 DS3
RAM: Crucial Ballistix 2Gb 800Mhz
GPU: NVIDIA 8800GTS 320Mb
HDD: 320Gb Seagate
PSU: Silverstone Strider 560watt
DVD/RW: LG H66N SATA

I have some minor problem with my PSU when my PC is not turned on. The PSU seems to have a very low hissing noise when the PC is not turned (psu plugged in and power switched on). The sound would eventually go away once I turn on the PC. Should I be concern with this and change with another unit since I still have 1 to 1 swap for the 1st week ?

Thank You

Are you sure its normal..~ I dont feel comfortable with the hissing sound.. Would probably swap the unit since its <7 days