New CPU caused loud fan and black screen

[aramis7350]

Hello All,

I have a couple of working HP RP5800's discarded by my workplace. Both came with an Intel Pentium G850 CPU.

I upgraded one to an Intel I3-2120 (listed as an option) and it worked fine. I have an Intel I3-3220 CPU (not listed as an option) and attempted to upgrade the other RP5800 with it but ran into a problem. It would not boot up but instead gave me a very loud fan and a black screen. My problem now is that even though I re-installed the original G850 CPU, I am still getting the black screen and loud fan with no boot up.

Did I fry the motherboard or is my fix simply a matter of resetting the bios or something like that?

[Grzwacz]

Greetings,

Welcome to the forum.

I am not a HP employee.

Try resetting CMOS by removing the CR2032 motherboard battery.

Let the PC sit for a while before reinstalling the battery.

Regards

[aramis7350]

I tried that. I also tried depressing the CMOS reset button on the motherboard. I am still faced with a loud fan and black screen and I am unable to boot up.

My research had led me to believe that installing a CPU that was outwardly similar but possibly incompatible would merely result in a non-starting scenario and was what I had faced in the past with my Dells. It seems that may not be the case with my HP's.

[Grzwacz]

Hi,

Well, then you may have damaged the CPU or the socket.

Or some other, unrelated hardware problem has occurred.

Regards

[aramis7350]

It looks like that CPU is still functional as I re-installed it into its original computer and it seems to be working fine.

Which has me wondering how the CPU fried my HP motherboard without itself suffering any damage ...