That psu needs to go. It's below what most would call mediocre in quality and ability,nevermind longevity. Here's the skinny on psus, the '00's' suck. Stick to psus that are '50's'. You'll want a 750w if anything, I'd recommend the Evga 750 B2. If you want to skimp on wattage, the Corsair CX650-M is good, as are any of the XFX (not XT series) or the Evga 650 GS or G2 or any Seasonic.
Don't skimp on a quality psu simply because of price. You'll end up paying more for replacements, repairs, time and aggravation fixing errors and run the risk of having a useless pc when RMA is the case.