In need of help: PS4 cleaning

Hi guys!

I'm being bothered by an extremely loud PS4 and read some different cleaning tutorials in order to try and fix it. Unfortunately, the sound is still there. I was hoping someone around here could point me in the right direction to fix this?

I've got my PS4 for about 3 years. Since a couple of months it started getting really loud so I decided to open it up to clean it. I took out the power supply unit and cleaned it with some compressed air, I then used the compressed air to clean out the fan as well.

Since this didn't fix anything I figured it might be something else but I'm not too sure:

• Thermal paste: how do I know if mine needs to be replaced? any tell-tale signs?
• The fan itself: apparently different kinds of fans are used in the PS4. Which one is best and how do I know which one is used in mine? Honestly I don't think this is the problem since it only started a couple of months ago.

Any help/tips would be greatly appreciated! Kind regards, Pillouter