Computer not cold booting- low voltage?

My computer boots (or at least it turns on with lights and fans spinning), but I see nothing on the screen.
I have my i7 computer overclocked to 3.0GHz, and the voltage undervolted to 1.1 to 1.125 volts.
The RAM is rated at 1066MHz at 1.5v, and I have it at 1200MHz at 1.5v

I'm pretty sure this is not a graphics card problem.

I recently increased to RAM voltage to 1.54v and CPU voltage to 1.125-1.13 volts...would this help?


Feb 14, 2009
Can you tell us previous attempts? because at this point it may be your cpu unless it booted fine right before you did something...

We need to know what you did right before it stopped booting.

Thats like me saying i overclocked to 5ghz and now all of the sudden my pc wont turn on. help me!!

get it?
It booted fine when I left the voltage on auto - but auto was way too high and my temperatures increased way too much.

I OCed it to 3.0GHz, and undervolted it to 1.1 - it booted fine after that but it was a restart, so soft-boot.
I can hard boot it at 1.1v if I restart the computer 3-4 times (I guess it either reverts to default settings temporarily, or the cpu finally gets enough voltage)

Anyways, I'm typing on it right now, successful hard boot at 1.125v cpu

Hmmm I see. So undervolting the cpu or RAM can potentially cause cold boot issues if the voltage is too low...

Dangerous Beans

Jun 12, 2009
I thought that cold boot issues was where the cpu wouldn't boot below -80c, or around there. No matter what speed it is running, or what voltage, it won't boot at those temps.

What you have sounds like a voltage issue, the cpu/ram just isn't getting enough volts to run at that speed. Though it is strange that it will restart but not boot from power off.

Maybe try overshocked's suggestion

So far I'm slowly increasing the voltages of my RAM and CPU.

Do I need to change the voltages of the IOH or QPI voltage override?
Well, I've brought it up to 1.3v cpu and it still fails to boot after I turn it off for a while. (it again passes an hr of Prime95 without any issues)

I'm beginning to think that the QPI/IOH/RAM is responsible - I should up the voltages on those.