Question Seemingly ok PC all of a sudden doesn't boot.

[volkankorki]

First of all, sorry if this post is not made in the correct section.

I was cleaning my CPU fan and replacing the thermal paste and now my PC does not boot. I have checked all of the cables including the 24-pin, the 8-pin ATX supply, the 8-pin connected to my GPU and all the small headers such as the CPU fan header.

After connecting the PSU cable and switching it on, my ram lights up without me pressing any sort of power button (first time seeing this happen) and my GPU fans start moving ever so slightly before stopping.

I don't think there is a POST as there is no sign of display. I have also tried switching the ram slots.

My specs are as follows:
Gigabyte b450m h Bios version should be F2
R5 3600x with stock cooler
XPG 2x8 3000mhz ram
Asus Dual GTX1070

 

[punkncat]

Without knowing more:

The stock cooler (paste) for Ryzen has a famous issue with sticking to the CPU. It is a guess that you might have pulled the CPU up out of the socket just a bit during your remove/repaste. Perhaps open her back up and remove and reseat the CPU?

 

[volkankorki]

Without knowing more:

The stock cooler for Ryzen has a famous issue with sticking to the CPU. It is a guess that you might have pulled the CPU up out of the socket just a bit during your remove/repaste. Perhaps open her back up and remove and reseat the CPU?

Hey, thanks for the reply. I made sure to not even wiggle the CPU as I was removing the cooler. It was still seated perfectly by the time I got the cooler off. I also reseated the CPU perfectly after I finished to clean the rest of the thermal paste on it. I have just removed the CMOS battery and will try to unplug-plug everything back.

 

[punkncat]

Did you happen to remove any of the front header (power/reset) connectors while doing this? You might check to be sure they are still on the correct pins.

 

[volkankorki]

Did you happen to remove any of the front header (power/reset) connectors while doing this? You might check to be sure they are still on the correct pins.

Makes sense that one of those pins might be messed up, hence the auto boot. Will check the manual and connect them accordingly

 

[volkankorki]

So, remembered I had a 4-pin Mobo speaker. Tried plugging that in to the speaker header along with the Reset and Power pins. It still booted on its own upon flipping the switch on the PSU. Tried taking the power and reset out of the equation (to see if it's a short that keeps starting the machine) to no avail. Tried booting with a single stick of ram on the far side. Should I try booting without CPU fan plugged in ? Would it even boot like that ? And how can I get a post ? Because the only thing that happens right now is:
1)Ram Leds turns on (they are only on when the computer is powered on, not when plugged in)

1. CPU fan doesn't spin
2. GPU fan barely nudges itself

 

[volkankorki]

I'm writing this if someone has any idea on which direction i should take. I still had the CPU, Mobo, etc from my last build; the only thing I am using with the old components is my 1070, my PSU and SSD. I can still get no display even on the old motherboard and components although the fans do spin when I short the power switch to start the computer. The power LED on the GPU is still white, meaning it's getting enough power, yet there is still no display which bugs me. I don't know whether to get a new PSU or GPU at this point but I'm looking forward to suggestions.