You can't hear the noise when the system is powered up. Also the noise remains even after the PSU is switched off (PSU switch) the noise continues for about 3 mins then stop completely. Here's the system spec:
Case BitFenix Merc Beta Midi Tower Chassis - Black PSU Sea Sonic G-Series G-360 360W ATX 2.3 Motherboard Gigabyte GA-78LMT-USB3, 760G CPU AMD Athlon II X2 270, 2x 3.40GHz, boxed CPU Fan Scythe Shuriken Rev.B (SCSK-1100) GPU ASUS EAH5450 SILENT/DI/1GD3(LP), Radeon HD 5450, 1GB DDR3, VGA, DVI, HDMI RAM (4GB) Crucial Ballistix Sports DIMM kit 4GB PC3-10667U CL9 (DDR3-1333) HDD Seagate 500GB Barracuda Internal Hard Drive (SATA III, 7200 RPM) HDD Seagate 500GB Barracuda Internal Hard Drive (SATA III, 7200 RPM) DVD Samsung SH-222BB black, SATA, bulk (BEBE)
Any help greatly appreciated.
More aboutseasonic slight high pitch noise shutdown
I should add the system is running perfectly and no crashes of any kind. I just want to know if the PSU is okay. The build was for my parents and they haven't even noticed it.