Pc help

So I have had my pc for around 2 years now and occasionally when I turn it on the fans will spin but no boot and no lights come on in the pc, in the past I just kept turning it on and off and when it came on it put me in bios settings and told me somthing wasn’t optimal, now when I turn it on all it does is just fan spin and no boot does anyone know why… I can provide video if needed