Not booting after overclock

Hi,

A few weeks ago I bought myself an AMD quad core system and I am now trying to overclock it - but whenever I try, windows won't boot.

What happens is - I turn the pc on, it beeps. Shows the full screen logo, then goes into DMI Pool testing. Then it starts to load windows, and when the loading is over, its just a black screen. If I press the reset button, it dosen't beep or POST and all you can hear is my hdd whirring away. When I turn it off and on again, it beeps and lets me into the BIOS in which I can put all the settings back to normal and it then boots absolutely fine.

Here are my specs -

AMD Phenom II X4 940 Black edition 3ghz
Crucial Ballistix PC2-6400 2gb module
Gigabyte GA-M52L-S3P
ACE 620W PSU
ATI Radeon 4670 512MB Graphics card
AMD stock cooler w/ 2 heatpipes
LiteOn DVD-RW
Windows XP Home edition

Earlier, I tried overclocking it to 3.4ghz by upping the voltage +0.25v and putting the multiplier up to about +16x. Worked fine in the bios, idle temps around 48c. So not temps thats the problem here.

From what I've researched on the internet and this forum, it might be the RAM being accidently overclocked beyond what my mobo can take - but as far as I know it can only be done by upping the FSB - but I haven't touched it - and even if that were the case, there isn't a ram frequency control in my bios, only a voltage control.

So what do you think?

Thanks,

Alex

^ +1

What voltage does the RAM Mfg. call for? Set the voltage to RAM Mfg. specifications. 1.8v is BIOS default for PC26400. Crucial Ballistic will require more voltage than default 1.8v.

48c seems high for idle temperatures. My X3 720 is currently idling in windows at 36c. When yours is put under load, the temperature could easily run into the 60s. This may not be the main problem, but could cause further problems.