PSU buzzing when plugged into mobo w/ PC off

Silicrex · January 18, 2020

Hi! First-time builder here. When my PC is off, my Corsair RM750x PSU makes a faint, constant buzzing sound. It immediately stops when the PC is turned on, and immediately starts again when the PC is turned off. Based on research, it seemed to be possible coil whine from the standby power; but then I found the buzzing does not occur when it's only plugged into the outlet. When I plug it into only the motherboard, the buzzing occurs again. Any ideas on what might be going on? I'll attach a recording of the sound. Here is my part list:

Corsair RMx 750W

Gigabyte Z390 AORUS MASTER ATX LGA1151

Intel i7-9700K
Noctua NH-D15S

EVGA RTX 2080 SUPER 8 GB XC ULTRA
Corsair Vengeance RGB Pro 16 GB (2 x 8 GB) DDR4-3200 Memory
Crucial MX500 1 TB M.2-2280
Samsung 970 Evo Plus 1 TB

Corsair support suggested to RMA the PSU. After my initial assembly, the PC was stuck in a boot loop for around a minute before reaching BIOS. When I turn my PSU itself on, sometimes there is a brief white flash from one of the RGB parts of the motherboard. If it seems both could be having issues- should I try to RMA both and go from there? Any ideas or information would be greatly appreciated. Thank you.

RM750x.mp3

Edited January 18, 2020 by Silicrex
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