I installed a new CPU (AMD Phenom 2 black) to replace my old one (AMD Sempron 140) it did not have any problems beforehand. I have a HP Pavilion p6517c. My monitor does not receive an input signal and my mouse and keyboard do not receiveany power.
What did not have any problems before?
You mean with the old CPU?
Remember the Motherboard thinks it has the old CPU so you need to clear the bios so it can discover the new CPU.
You did check to see if the bios supports that CPU? You might need to update.
and that the mother board supports that CPU voltage wise.
and the power supply can provide enough current?
HP's are built with PS with just enough power to work as supplied, so you might need to get a replacement.
I would start with HP website.
Now if it was working with the new CPU but now doesn't it can still be not enough power.
what socket is your mother board ? can you post a model number or serial number for the motherboard?
there could be an issue where you have an older socket 939 or earlier and your trying to replace it with a am3 processor .. your motherboard will need to be at least and AM2+ for that processor to work and that saying that particular motherboard supports that processor. also as the previous poster noted HP computers are notorious for having bare minimum power supplies in them you will more then likely need to upgrade as that processors TDP is way higher then the previous model and you also may run into issues where your OEM license will not accept the new processor and force you to re-purchase another license of windows