Black Screen@Restarts+ "Overclocking Failed" after!

[Ransome]

Hello,
I have OC'd my Core i5 3570K a few days ago - to 4.2 Ghz, with offset -0.025, and XMP profile activated for RAM.
I did this according to the help of some great people here.

Everything worked, Prime95, 3dmark, games.. for several days - flawlessly, temptures where below 61 celsious on prime 95. (I am using Noctua NH-d14 cooler and Sabertooth z77 mobo).

Until today. My system keeps failing on Restarts and Resets, whether it is manual, through windows, bios, or automatically after installing stuff.
Computer shuts down, screen goes black (off - like it should be) - but it NEVER goes back on.
System simply fails to RE-boot. There is also a glowing RED LIGHT on the mobo, near the thick power cable, the ram, and the "DRAM LED MEM OK" button and text.

This Red light always indicate the black screen freeze. This issue occurs before BIOS (not before windows) - monitor wont go back on.

Finally, after forcing restart - by pluging out power or holding the power button - the system starts over, and a black screen appears saying:
"Overclocking Failed! Press F1 and re-adjust your system" (and some info on USB, mouse, keyboard, ram etc.)

This happened to me all day long.
Please help if you can. Can't find answers anywhere.

 

[nna2]

the memok button will reset the default settings fyi

try using a manual VCore instead of an offset one

 

[Ransome]

So what about that red light?
And why do I get freezes only on Restarts and Resets and no problems on Prime95 and stressing?


If I use "shut down" instead of reset, I don't think it happens. But again, this issue occurs many times. Can you help explain more?

I am trying now 4.3 with offset +0.01.

Problem is, even with no offset, or weaker oc the problem occurs. I don't know maybe it is a motherboard failure, but I was very careful with my oc's.

And what are reasonable temps to have in prime 95?

Thank you

 

[nna2]

for your information=fyi

im not very good with the offset thing, im more fluent with manual overclocking... i would suggest trying that

 

[Ransome]

Edited my last message.
My theroy is that voltages are excellent for high performance and idle desktop.
But when pc restarts and try to start over, voltages probably dip, and then it fails to start.
What I can't explain is how I didn't see it the past few days. ..