Motherboard doesn't start with some CPUs

[gogeccc]

I have an Asus P5K-E board.
https://www.asus.com/Motherboards/P5KEWIFIAP/

It starts, detects 7 GB of RAM and works completely normally with Intel Pentium 4 631 cpu. However, it doesn't start with e8500, e3400 or Xeon E5440. CPU remains completely cold, like it doesn't start at all, motherboard doesn't release any beeps, no signs of life at all.

First I thought I need to update bios. Done. Still not starting with any of the cpus even though it should.

Then I manually uptated cpu microcodes, the microcode for all three cpus is the same since they are all e0 stepping. Still nothing.

I got another board in the meantime, p5k pro, it started with the cpus even without updating bios, just reported an unknown cpu. After updating microcodes, it works perfectly fine with e5440, so it's not cpus or any other component.

It's a really weird issue in my opinion. It wouldn't be that strange if it didn't work fine with pentium 4, but it does, and doesn't give signs of life with others. I never had a similar issue, so if anyone has, please tell me, what the hell might be going on?

 

[tambeshakunt]

are the cpus on the published cpu support list on the ASUS website?

 

[gogeccc]

are the cpus on the published cpu support list on the ASUS website?

"did you do what only someone who has no clue about what he's doing wouldn't do?" (not being disrespectful, just joking 😀)
yes, I did check the cpu support list before buying the mobo and all the cpus (except e5440, ofc) were in the list.

What happened the second board that I mentioned is this:
"I got another board in the meantime, p5k pro, it started with the cpus even without updating bios, just reported an unknown cpu. After updating microcodes, it works perfectly fine with e5440, so it's not cpus or any other component."

Even though it didn't detect the cpus with the old bios, it did start with them.

This mobo doesnt start with anything but the s*itty pentium 4 631.

 

[antonio.parrot]

did you connect the auxiliar power cable 4 pins or 8 pins? maybe 4 pins is enough for pentium...

 

[xravenxdota]

i have a similar problem on some motherboards.The msi i found was a problem from msi's bios.Even reverting the bios still gave problems(Fixed by replacing the bios chip)Second one are same as yours.I tried bios everything but still only reads up to 3ghz presscot cpu.Non of my dual cores works.

 

[gogeccc]

did you connect the auxiliar power cable 4 pins or 8 pins? maybe 4 pins is enough for pentium...

nah, its not that. If you look to the leads on the motherboard's pcb below the cpu power connector, you'll see that all +12 pins are fused together, just as all the ground pins. Problems from insufficient power delivery could only arise when the cpu is under heavy load (draws more than 4pin is specified for, which must be over 100w).

i have a similar problem on some motherboards.The msi i found was a problem from msi's bios.Even reverting the bios still gave problems(Fixed by replacing the bios chip)Second one are same as yours.I tried bios everything but still only reads up to 3ghz presscot cpu.Non of my dual cores works.

I'll try replacing the bios chip when I get some time, thanks for the suggestion.