New CPU = No Display

Hello and thanks in advance for reading this.

All specs posted at end of the post.

I recently purchased a new CPU to replace my old, overheating CPU. After installing the new CPU and turning the desktop on, I immediately noticed that the CPU heat sink fan and chassis fan start up for a second, stop for a second and then start up again. After the second “restart” all computer parts sound like they are running fine. There is no display to the monitor with this new CPU. I double checked the monitor connection to the desktop and the video card to the mobo.

I reinstalled my old CPU and there WAS display on the monitor. I am assuming that it is the new CPU that is causing the problem. Upon further inspection, it was noticed that with the OLD CPU, the chassis fan spun much faster than with the NEW CPU. With the new CPU, even on the high setting, the chassis fan is spinning much slower. With this, I am assuming that the NEW CPU is not running because of the PSU.

Any thoughts? Again thanks in advance.


MOBO: ASUS P5B Deluxe Wifi-Ap Edition
OLD CPU: Intel Core 2 Duo
NEW CPU: Intel Core 2 Quad
PSU: 500 Watt Earthwatts

You’ll probably have to upgrade the bios of the motherboard, depending on which one you have installed now.

The latest is 1238 beta, released on 2009/02/11.

Definitely your BIOS and not the PSU.

How am I supposed to flash it? If i use my old CPU, it will overheat and shutdown before I get a chance to flash it.

You need to find a CPU that is supported by the current BIOs so the update can be done. If you don’t have one kicking around you’ll have to take it to some that can do it for you.


How did you determine that the old CPU overheats and causes the shutdowns? If the fan works and isn’t too dirty, I wouldn’t expect the strain of booting up would be enough to cause heat related problems.

I guess I missed that, how do you know your cpu is overheating? Could simply be the PSU failing. How long does it take for the system to shut down? What else is happening.

Is your ram a single 2GB stick or 2x 1GB sticks?
If it’s 2x 1GB sticks, remove one stick and retry, if it boots to the BIOS, check that the ram voltage is set correctly to match your ram. I had the same problem a while ago with this same board. :wink:
While you’re at it, it may be wise to clear CMOS since you fitted a new CPU.

any MOBO i have handled, provides audio queues during the POST.
when power is turned on, the BIOS checks for the presence of a processor, the presence of ram, and the presence of a video adapter. if all is well a single beep can be heard.
does the board offer any beeps?
mayhap you can find a manual at ASUS re that mobo with info as to the fault indicated by the beeps.
also … maybe you could set BIOS to DEFAULT settiings using older processor before installing new processor.
after thoughts:
does the new proc. have same voltage settings as old proc.?
can you set voltages on that mobo?

my 2 cents:
pull out the video card and plug monitor into motherboard
any time you install new processors/memory you must boot into bios and “load optimized defaults” save and exit before booting into O.S.