Specs are fine LSD, its just the PSU as said that is letting you down.
Here are the specs on the graphics card you bought, its power draw in watts at full load when playing a game ect, and the amp rating it also requires from a 12v power rail for it to run stable without crashing the card or the rest of the system.
You will need a Psu of 500w minimum that can provide 31A or more on the 12v rails of the Psu. So have a good check on the specs of the Psu, Good known brands to buy are ocz, Silver stone, corsair. Try to sick with these I know they may be expensive.
But cheaper unbranded Psu supplys for $40 or less more than often dont live up to the specs they state on the information sticker of its output in amps or wattage. And also have less safety features such as overload protection, and other features. In the long run it pays to buy a quality well branded Psu for peace of mind LSD.
Geforce 650ti.
Thermal and Power Specs:
105 CMaximum GPU Temperature (in C)
110 WMaximum Graphics Card Power (W)
400 WMinimum System Power Requirement (W)4
One 6-pinSupplementary Power Connectors