Let's hear about this PC make, model, age and if you feel it's dust, why isn't that work done?
At the very least share the make, model of the PSU, age of the parts and a Web Speccy link to look at the numbers and more.
Read how at https://www.piriform.com/docs/speccy/using-speccy/publishing-a-speccy-profile-to-the-web
Hello, my PC will randomly shut off and restart in a short flicker like action. This randomly occur when gaming, or surfing the web. Can happen then not happen again for a few days. Already checked for viruses and also replaces the power supply. Could it be an issue related to a bit of dust within the PC itself ? Thankyou

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic