Home-built PC has power-related issues

Dec 5, 2018
Hi, my home-built PC has had issues related to powering down and going to sleep since I first built it this summer.

It's a Corsair 250D ITX case with an ASRock Fatal1ty X470 mini-ITX motherboard, ASRock Phantom Gaming RX 570 GPU, AMD Ryzen 5, Corsair Vengeance RAM, Corsair RM650i power supply. It is running the latest version of Windows 10 with 4K BenQ monitor.

The two problems it has are this:

-When the computer goes to sleep, I am sometimes unable to wake it. The power light on the case is blinking, but pressing keys on the keyboard and moving the mouse does nothing. All I can do is press the "reset" button or hold down the power button and turn it back on.
-Sometimes when I shut down the computer, the monitor goes black, the keyboard shuts off, but the computer lighting and fans are all still on. Holding down the power button doesn't even work here. The only fix is shutting off the PSU.

What is going on? Please help!