CPU power problem?

[UncleDaddySwiss]

I am wondering what happens if the CPU isnt getting enough- or any- power. Does the rest of the motherboard power up? Fans? What about the (+5v ?) "OK" signal the CPU needs to start up? I think I read that the CPU needs a certain signal to start, correct?
Thank you.

Edit: Ok, I'm fairly confident that I'm not getting a Power_Good signal from what I've been reading. (http://powersupply33.com/power-good-function-of-pc-power-supply.html) describes what happens if this signal isn't recieved, and I think my computer is being held in a "reset" state. So now my question is: is the PSU just bad and needs to be replaced or is there some sort of fix?
And also, this happens for the first few times I try to turn it on, but eventually it does boot up. Strange.

OK, for future reference, if I would need to replace the PSU, any recommendations on brand/model? I think I would like to go with ~850W again unless there are other recommendations?

Also, once it does start, is it OK to use our should i wait until i get a new PSU?
I'm not trying to be obnoxious, i just really want to fix my computer.
Thanks for any feedback.

 

[cin19]

The newer gen. CPU/GPU will draw the power from the +12 rails. The 5V is for the hard drive or DVD device, etc.
If you think the PSU has problem, you are better go into the BIOS to check out the 3.3V, 5V, and 12V voltages, or you should update the chipset driver before using the software like HWiNFO64 http://www.hwinfo.com/download.php to check those voltages.
The PSU Voltage Tolerances http://pcsupport.about.com/od/insidethepc/a/power-supply-voltage-tolerance.htm

Check out the PSU tier list, for your system (i7+gtx780), you should get one is at least tier two or up. We recommend the brand like Super Flower, Seasonic, etc. also you will find other brands to use those ( Super Flower, Seasonic) , like xfx, evga, antec, etc.
PSU tier list http://www.tomshardware.com/forum/id-2547993/psu-tier-list.html

 

[UncleDaddySwiss]

OK thank you, i will check these things tonight.

...to be clear, i wasn't talking about CPU power, i was talking about the 5v "power OK" signal that the CPU needs before powering up, if I'm understanding correctly.