Re: Constant power cuts
Aye, if it's not a wall voltage issue, try swapping the PSU out with another one to be sure. You never specified what the power supply is, but if you paid less than $40 for it and it weighs 12oz for 400+ watts, it's probably not a high quality unit.
On the same tangent as the power though, does that circuit share with anything else in the house that might introduce instability such as a motor or compressor? They can be very harsh on electronics components, especially if you're just using a power tap instead of a good surge protector (a power tap is just a strip of outlets, usually has no power light to show that it's on, but they might have a power switch, and on the back it'll just have markings that say "power tap" or "power strip" - if you can't find anything that says xxxx joules, or "surge protection" then it should probably be replaced.)