Girlfriends PC will seemingly randomly stop posting

For around 4 months now my girlfriends pc would stop posting. After pressing the powe button it would spin to life (rgb fans turn on) but the monitors wouldn't. Her pc also has an indicator light for disk usage and that does nothing.

The only way I've successfully got it to boot up in the past after this happening is reseating the cpu, but even this isnt successful and it takes about an hour of doing various reseats (cpu, GPU and ram) for it to boot into windoes and work perfectly fine for a couple of weeks.

I bought a buzzer for the mobo for a code but it does absolutely nothing when this happens (1 short buzz when it starts normally)

Most recently she mentioned, the time shes using it before it happened it took longer to beep and the top monitor wasnt working (main monitor into GPU and top monitor into mobile igpu).

Motherboard is an Asus Prime a520m-k cpu is a ryzen 5 5500g 16gb ram unsure of the gpu

happy to help with any other details needed just want an answer, if it means a new cpu (my theory) then so be it