This is the first PC I've built, and it ran fine for one day before having this problem. I discovered that when I leave the HDD and DVD drives unplugged, the computer will start up fine, and I can enter BIOS. However, when I plug in the power cables for either the DVD drive or the HDD, the computer powers on for a second or two, then shuts off without warning, and then powers on again, repeating the cycle.
Everything seems to point to a faulty PSU, but I need some advice/help before I RMA the thing, in case it isn't really the problem. Is there anything else that might be causing this? I'm a complete newbie to PC building, and I have no idea what to do at the moment.
PSU: Corsair Enthusiast Series TX650 V2 (650w)
CPU: i5-3550 3.30GHz Ivy Bridge
MOBO: ASRock Z77 Extreme4 ATX
RAM: 8 GB Crucial Ballistix 1333
HDD: Samsung Spinpoint 7200 RPM 1 TB
DVD Drive: Some Asus DVD-RW drive
GPU: HIS Radeon HD 7850