Computer turns off suddenly even in idle

[NightofNights]

I was good and dandy for the past months. But suddenly the computer turns off. So i just turn it on again and i will turn off even in posting. Sometimes i works sometimes not so I resisted the RAM, GPU and CPU but still it happens. I check my temps in idle or gaming and it just around 40°C to 63°C for the CPU and 36°C to 73°C for the GPU.I never did overclocking all of the parts are running in stock.I also updated the drivers including my bios and it still happens. I really don't know whats going on and maybe you guys can help me.
My Specs:
Windows 10 64 bit
Silverstone SFX 600W
Ryzen 2700x

Strix RTX 2070
Strix X470-I
8x2 Trident Z 3200mhz
240GB Kingston SSD
1TB Western Digital BLUE