Hey guys,

First time poster, long time fan (sorry, couldn't resist). My CPU has long seemed to be the bottleneck of my computer, so I recently took up overclocking. This isn't a thread to ask so much *how* to overclock (I know the basics and have successfully done it a bit), but how to deal with an overclock gone bad.

Long story short, I saved settings to the CMOS that made the RAM run too fast and now my computer will not boot. It successfully booted (I heard the good motherboard beep) once, but there was no screen. On subsequent boots, it will not get even that far. All the components I can hear and see run are running, the GPU, CPU, power supply, fans, my motherboard has all the indicator lights on -- but it's not starting. The POST LED displays F3 and F6 before 01, which I understand to mean it doesn't see the RAM, or thinks there's an error with it. Another strange symptom is that my USB ports on the back and front aren't getting power anymore -- though that may have to do with resetting the CMOS. This is the most worrying part to me because I can't figure it out.

I have turned off my computer and pressed the Reset CMOS button multiple times to the same effect, also leading me to believe it must be a RAM or other hardware issue.

So, my question to you guys: am I on the right track here? With these symptoms, does it sound like the RAM, or am I totally off-base here? Also, what do you make of the no power to USB situation?

Here are my specifications:

GPU: GTX 770
CPU: Intel i7 950
Motherboard: EVGA x58 SLI 3
Power Supply: Corsair TX750W
RAM: 8 GB DDR3 Corsair @ 1866 MHz
Windows 10 on a 500 GB Samsung SSD 850 Evo
(Extra terabyte for storage)

Thanks!

Thanks for the tip! I tried that, but it didn't have any effect.

Thanks! Perhaps I should have been more specific in my first post -- I have also tried this. I pressed and held down the CMOS button, both the external one and the one inside my case, I have removed the battery, waited a bit, and put it back in. That's why I believe it's no longer a CMOS issue, but a RAM one.

Tried one of my RAM sticks in every slot -- no dice. Still getting F3/F6 on POST, everything powers up except there's no screen and no USB port power.

Also, though I'm not sure how much this helps -- if I've reset the CMOS, the power stops and starts at the beginning -- as in it very quickly stops, and just as abruptly starts again.

I've searched around online and F3/F6 has to do with memory -- either the RAM being bad or poorly seated, or worse, the motherboard trying to run it in a way it can't be. Still, I figured the latter isn't possible after resetting the CMOS.

Hudley
Also, though I'm not sure how much this helps -- if I've reset the CMOS, the power stops and starts at the beginning -- as in it very quickly stops, and just as abruptly starts again.

That's normal, all of my EVGA X58 boards do that.
 
What settings did you use exactly for your oc if you remember?
 
The only things I can think of doing now are re-seating the CPU, GPU, Power cables, Ect. and if that fails then test the system outside of the case (Eg. On a cardboard box), which is a pain I know but I've looked around a little about this issue and it seems to be caused by a short to ground from what I've read. It's weird that it would only show up after trying to oc though. 

@LFaWolf There's actually some RAM on its way. I'll see how that works in a couple of days, (as well as tucker's suggestions) and should all that fail, yeah, off to support for me.

Alright, I've put in a few other sticks of RAM I had lying around, and they didn't work -- though one of them got the POST stuck on F3, rather than cycling between F3 and F6 super quickly and then going to 01. I also reseated everything within the case, CPU, GPU, power, unplugged the motherboard from everything and assembled from scratch. This also got to the same non-effect (but not worse off, which is nice).

That just makes me think it may be the short to ground thing rather than RAM -- only one way to find out. What's the most painless way to move my entire system onto a cardboard box? I have nice wiring and everything tucked behind the motherboard and I don't necessarily want to uproot all of that, if possible.

I'll try just that! See you in two hours :D

I hope I am not too late with this suggestion - you could try a basic video card if you have one before taking the board out.

Alright! After a long and arduous wait for the RAM and CPU (the only reasonably priced 950s are used and ship slowly on eBay), I tried both... And nothing. Far past the point of no return on warranty for any of these items, as I got them in 2010. The only reasons can now be the motherboard and power supply. That's pretty much the end of it.

Thank you all so much for the help! It was a pleasure chatting with you and learning more about "failure to post" bug testing, if nothing else.