dusR :
i have the gtx 690 and its a very powerful and energy angry card, in my opinion you need atleast 800W for this card to work good and keep the other parts work fine aswell, so if i were you i would of taken a new power supply since this card is a beast and i fully recommand it, or you just have to go on a little less powerfull card i think even the gtx 680 will work with 650W, but still its all depending if you power supply is from good manufacture or not.
No offense, but you are wrong. Once again, wattage of the PSU is not really important these days. Furthermore, the 690 is an extremely efficient card. It really doesn't suck as much power as you might think.
For example, the GTX 670 uses a little over 150W or 160W on average in gaming. The 690 only uses a little under double that. You can easily power it with a decent 650W. Heck, with a low power CPU such as an Ivy Bridge i5, there are several 550W models that you can get away with and have room to spare.
The 690 uses only about 50% more power than the 680 and the 680 is fine on most 520W-550W PSUs that aren't junk. For example, the Antec Neo Eco 520W and up are plenty. You just have to get the right model.
Also, being from a good manufacturer doesn't mean it's a great unit. For example, some Seasonic-built units (for different companies of course, Seasonic designs all of their own units and does an excellent job) suck because they have crappy, non-Seasonic designs that were merely manufactured in Seasonic plants. Then there are companies such as XFX that use both Seasonic designs and Seasonic manufacturing and pretty much all of their models are among the best in their class.