Power button LED is blinking while I use the PC after I upgraded my motherboard, CPU, and RAM. But the PC seems to be working fine. It doesn't happen all the time,
Asrock Z270 Extreme 4 front panel header schematic | Overclock.net
Are these Front Panel Connectors Different? - CPUs, Motherboards, and Memory - Linus Tech Tips
LED specs for atx power on status - Electrical Engineering Stack Exchange
Why motherboards have two pins for LEDs, led+ and led- - Electrical Engineering Stack Exchange