Desktop doesn't display and won't turn off

[Waveyboya]

Running Windows 10 and using a tv as a monitor via hdmi.

So a few days ago my desktop was in sleep mode but would not turn on. After trying a few things, I just held down the power button to shut it down completely, but it wouldn't work. Restart button didn't work either, so I hesitantly flipped the power switch to turn it off, but then it wouldn't turn on. As I was checking inside to verify the green light on the motherboard was on to be sure it was receiving power (it was), it turned on on it's own somehow and worked fine. Weird.

However, next time I trying turning it on (from completely off) it wasn't turning on. I flipped the power switch off and on and tried again, and it turned on (fans started and computer lights came on) but would not display (the tv works just fine when connected to my laptop), just like the first time it was in sleep mode but wouldn't come on. I noticed that my key boards lights don't come on, and the computer doesn't make any sounds when I unplug things.

Any thoughts? Could it be the power supply is faulty and not giving full power? Or something worse?

Thank you for your help in advance.

 

[Cycloid Torus]

Possibly...power good signal? PSU loose connection? If you have a spare PSU, you might just try it.

If you get it going, backup key files, disable hibernate/sleep - then reboot and cross fingers.

 

[Waveyboya]

Ok, so I just noticed the CPU LED is on. Took out the processor and examined the pins, but they all looked straight. There was a minute bit of thermal paste on one of them, cleaned it off best I could and put it all back, making sure it was seated properly. Still doesn't work, so I think I should get a new processor? Does that sound right?

 

[Cycloid Torus]

No, it doesn't.

Troubleshooting requires a planned step by step approach. You have the machine there. What is it doing? What are the components involved? How do you test each until you find the real issue?

Unless you bent pins on CPU or on motherboard socket or zapped it with static, the CPU is not likely to be the problem.

For a 'no start' condition, review the following and make a plan based on your observations of your machine and its 'problem.
http://www.pcadvisor.co.uk/how-to/laptop/pc-wont-boot-heres-how-fix-it-3528959/
https://www.lifewire.com/how-to-fix-a-computer-that-wont-turn-on-2624450
https://www.howtogeek.com/173828/what-to-do-when-windows-wont-boot/