mobo won't boot after upgrading cpu

C

calpolyarc

New Member
I have an asus p5b mobo... today i replaced the psu (to an Antec 500w Earthwatts) and the cpu (to a q9650). According to the Asus website the p5b board is compatible with the q9650. Before instgalling the new cpu I did update the bios succesfully. So I hooked everything up, plugged the power cord into the psu and then hit the power button.... nothing, silence. The green LED on the mobo is on so I assume it's getting power. I cleared the CMOS by removing the battery and by moving/moving back the RTC/CMOS jumper. I hit the power button... nothing. I remove all of my RAM except 1 stick... hit the power button... nothing.

Then I install the old cpu and old psu and go through all of the same steps and.... nothing, even though the system was working perfectly earlier today.

What could be the problem? I assume that just because the green LED is on that doesn't mean the mobo is in 'perfect' working order? Are there any other possibilities? Anything else I should try?

Thanks.
 
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I would go thru and recheck all your power supply cords. Make sure everything is good. Unplug everything and then plug it back in one a time so nothing gets mixed up. Did you plug in the 4-pin power supply cord for the processor?
 
I unattached everything and took the mobo out of the case. Jump starting with the old cpu and psu didn't work... I can hear a 'click' in the psu telling me that I've made the jumpstart connection but as I hold it there nothing else happens. And this is with the mobo out of the case and only the essentials connected: 4 pin power, 24 pin power, fan power, cpu, fan, video card, 1 stick of ram.
 
I would suggest putting a power supply in the computer you know is functional. After you hook up the replacement power supply unit try to power up the computer and then see what happens.
 
I'm ashamed to even say what the problem was but I will just in case it helps someone in the future...

I had the floppy drive power cable from the PSU plugged into the 'power fan' pins on the mobo :confused: For some reason I had it stuck in my head that the psu needed to supply power separately to the fan. :angry:

And this is with the mobo out of the case and only the essentials connected: 4 pin power, 24 pin power, fan power, cpu, fan, video card, 1 stick of ram.
Click to expand...
See where it says 'fan power' and also 'fan'... yeah that's the problem, lol. If only I had a floppy drive that cable would've been spoken for!

:mad: .... deep breath, time to move on...

Thanks everyone for your time and suggestions.
 
I was going to suggest that something was connected wrong. Apparently that is the case. Glad you worked it out.
 
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