BSOD and flickering graphics on Windows 7 64bit

I recently purchased a new motherboard (Asus P8 Z68-V Pro) Processor (Intel Core i5 2500K) and 8gb of DDR3 RAM.

Since installing these I have had a lot of problems with at first flickering graphics, the screen going black and then coming back and then a BSOD.

I've checked temperatures and none of these are a problem. I've reinstalled the graphics card drivers, updated the motherboards BIOS. I've installed the ASUS software that came with the motherboard and this has come up with warnings on the +3.3V occasionally, could this be a problem?

This is a new install of Windows 7 since I had to reinstall so I had 64bit for the amount of RAM

The graphics card I have is the ATI Radeon HD 6850 and I have the 11.7 drivers installed.

I especially seem to get the BSOD when playing CIV 5.

I'm wondering where the issue lies, does this sound like a power supply problems? faulty graphics card? faulty motherboard?

I'm not sure which it is. I hope I've provided enough information. Please ask if you require more

UPDATE: I have tried the internal graphics chip instead of the graphics card and I still am getting BSoD.

I have had many Stop Codes

• 3 0x0000003b
• 2 0x00000101
• 1 0x0000001a

I'm not sure but I think I can hear a high pitched noise coming from the power supply.

UPDATE 2: I've tested the RAM and it seems that one of the sticks was a dud, this seems to have stopped the BSoD for now.

This could indeed be a power supply stability problem, but it could also just be a faulty component - graphic cards, motherboard, RAM, any of these could in theory contribute to this. It could also (although it's not likely) be a driver or OS problem, so a clean installation of Windows is a good test if it's feasible. Personally, I would swap the graphics card and/or power supply (whichever is easiest for you) as a first test.