Welcome to the forums, newcomer!
It's hard to troubleshoot a system with only two lines of information, one being the thread title and the other line being in the thread's body. Please parse the specs to your build like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:
include the age of the PSU, apart from it's make and model. In the interim period, try and relocate your system to another wall outlet and see if the issue is alleviated. A video of the issue could also help us two fold, to see if you're physically depressing the power button or reset button to get to OS GUI.