new motherboard, CPU, and RAM, but no POST

sdguy0038

Commendable
Feb 15, 2016
10
0
1,510
Upgrading system I built several years ago, so some but not much competence.

MOBO: Gigabyte Z370 Aorus Gaming 5
CPU: i7-8700K
GPU: Asus Radeon RX 580
RAM: Patriot 2x8GB DDR4 3400
PSU: XFX Pro650W

GPU was running with old motherboard. Suspected CPU damaged by long-term overheating, hence upgrade. Installed components, powers on but never gets to BIOS. No beeps. Whirrs for maybe 30 seconds, then shuts off and tries again.

Went through the checklist. Reseated GPU, memory in different slots. Fans are working, including CPU cooler.

BIOS thing?

Any suggestions welcome!