A GS600 is more than enough to power that build as it has a 12v rail that supplies 48amps which equals to around 576W on the 12V rail.
When gaming, your build will not take more than 300-350w's on the 12v rail. You will only exceed 400w when doing unrealistic loads via stress testing. As such, the GS600 is not underpowered for your computer and in fact, you have much room to overclock both the CPU and the GPU.
I have powered heavier componets with a slightly heavier power supply. My system consisted of a i7-920 with 12GB ram coupled to, at different times, a GTX280, a GTX580 and a Radeon HD5970 along with an SSD, multiple hard drives and an optical drive. This was powered by a Silverstone 650W and drew no more than 400W from the socket. Considering the lighter graphics card and comparable processor, I'd be surprised if yours draws much more than 300W.
thanks for your replies , i guess it takes me back to my original problem, i have RMA 'ed my gtx560ti and have new ssd and mobo but issue persists i think its a better idea to go with the thought that psu is bad or my home power isnt clean
I would look toward the Rosewill CAPSTONE series. Made by SuperFlower, 5 year warranty, 80plus Gold and JonnyGuru approved. The best deal is the 750w modular unit for $90. However, you could power your system with a 450w or 550w without hesitation.
Wow that other thread is ... I don't have the words for it. I have a similar setup to yours, just with more stuff. I run a good 400 W power supply and that's more than adequate (before anyone argues, I measured power draw under stress test and could only get up to 270 W).
I have serious doubts that it is either your PSU or graphics card (2 duds in a row?) as they present different symptoms when failing. The thread did have one piece of useful advice, try another monitor see if you have the same issues. It sounds more like your monitor is having issues with determining what type of signal it's receiving. My guess is there is an issue with either the monitor or the cable.
What kind of monitor are you using and how is it connected (DVI, HDMI, etc)?