I can confirm the coil whine is coming from the motherboard. I went through 8 months of swapping ALL parts, using previous working parts, and all sorts of drivers to solve Q code 00, audio issues, and the coil whine.
I used ALL of the same components on two other brands, MSI (Titanium Z170) and the Gigabyte Gaming Z170 boards that never gave any Q code 00 issues, no RAM issues, and no coil whine. They were whisper quiet with the same GPU/hardware.
Each Asus board I swapped through had some form of coil whine.
to test this, just purchase another brand and test the same hardware/GPU especially, and listen for coil whine. Then it would be safe to say if it's the mobo, gpu, or something else.
I experienced it only on the Asus Z170 boards. My old Asus board had 0 issues, so I am disappointed with the new version and the issues that come with it.
Z790 Asus Hero Maximus on 0816 BIOS (0914 and 1202 crashes for me on XMP I), Intel 13900k stock clock, Asus 4090 Strix OC edition, FF3D532G720 Teamgroup Ram running XMP I, 16gb x 2, Samsung 980 Pro 2TB x 2, Seasonic VERTEX GX 1200W, Win 11 Pro 64, Deepcool LS720 AIO, NZXT H7 Flow. Comfortably using Armoury Crate for updates/fan xpert.