Hey guys, I was wondering if someone could help point out where I've gone wrong with my latest problem - I've been having a first stab at overclocking, using a QX6700 on a standard Asus P5B board, with 2GB of Crucial XMS2 5-5-5-18 RAM. I tried a few things with mixed results but was always able to restore my defaults when things went wrong and boot into Windows normally. However, on the last attempt, I changed all my voltages to manual (Northbridge, FSB termination etc.) but set them to what I thought were pretty conservative numbers. The system POSTed but failed to boot to Windows, so I reset and was able to go back into the BIOS and restore the defaults. Now, though, the system gets past the POST only to display a message saying "Unknown CPU detected. A BIOS update is required to unleash its full power". I've re-flashed the BIOS using EZFlash 2 and the CPU is recognised in the BIOS, but the error still keeps repeating and I can't get into Windows any more. I'm running the most recent BIOS version and I didn't have this problem before - have I killed something somehow? I've Googled but not found a definite solution - all suggestions are to update the BIOS, which has been done. Can anyone help? Cheers in advance...
Have now tried reflashing BIOS again and leaving CMOS battery out overnight, but no change. If I'm able to POST and see the CPU in BIOS, then I can't understand why it's not recognised at a later stage. Should I look into downgrading the BIOS?
Thats sounds a bit dodgy to me. I've never seen a mobo display anything like that. Possible bios hack...They do exist. Like you say though, try going back to a previous version thats know to work. It could be that you've put the wrong bios on so thats why it's not recognizing the cpu.
Deffo try resetting the CMOS / removing the battery (PC off unpowered)...then rolling back to an earlier BIOS that you know works... if that doesnt fix it try another working CPU chip. If the new CPU chip cant be read properly then something has given way on your motherboard. Odd error though by all accounts. goodluck
Curiouser and curiouser. I've now left the CMOS battery out and the jumper in reset setting for the whole weekend and the issue still occurs upon boot. I've also regressed the BIOS back to a previous version, even though this version DID work before, but still can't boot into Windows (although the "unknown CPU" message has disappeared, oddly). In the absence of another CPU, I might try looking for another board. Is it possible I've done something by UNDERvolting the chipsets?
Aha! Partial success (of sorts). Thought I'd put this up as I was fed up reading around the internet and finding no solutions on any of the threads. I can by no means explain any of this, so I'll just report what happened... Newer BIOS 2104 would not recognise the QX6700, but regressing to the 2001 BIOS got rid of the message but without letting me boot into Windows. Spoke to a helpful chap call Pawel from Asus support who suggested increasing the voltages until the CPU was recognised - this worked after a fashion, but I was still stumped on why I couldn't get Windows, until he pointed out my schoolboy error - check the F8 boot device menu. For some reason the board had reverted to picking up my storage drive as the OS drive, but left some of the other custom settings so it didn't occur to me to check this (silly billy). I can now get into Windows without the Unknown CPU message, but only under the older BIOS version with default settings and all my overclocking attempts so far have met with bad CMOS checksums - not sure what this indicates, but I'm going to go back to square one and try changing everything one small step at a time.
