Self build PC occasionally won't switch on

[Mark3001]

I've got a self build PC which is about 3 years old. Recently it developed a glitch where sometimes when I try to turn it on with the power button nothing happens. If I switch it off at the mains and on again it does work but this gets annoying. What could be causing the glitch?

System:

Corsair RM1000 PSU
Asus Maximus Hero VIII mobo
MSI GTX 1070 Gaming X GPU
Corsair Vengeance RAM

 

[jay32267]

It could be something as simple as the power switch.