@Johnnyboy8387
You said you took the back cover off -- which should enable you to see the case fan. Reboot the PC and look to see if the fan starts spinning.
If it does, that means your PC is power ON, it's just not booting into Windows -- and if you have another PC you can use to make boot media, you can try to repair that.
If it does not, that implies motherboard issues, and those are hardware and we can do nothing for you about those.
Let us know what happens.
I am a volunteer and I do not work for, nor represent, HP