Question Smoking Motherboard a Week into Build

Dec 14, 2019
Hey All,

Recently did a build for the first time in a long time. Finished it, was playing games for a while, using it for work, til finally tonight I was browsing reddit and randomly it shut off. Didnt think much of it (I thought I saw a flash from the case though) and rebooted. Almost immediately, my motherboard starts smoking roughly around the capacitors that line the bridge near the IO. I immediately shut everything off. Currently I'm RMAing the motherboard, but I'm trying to figure out how this could happen? Is it faulty or am I? I checked all my wiring (I'm anal about cable management as well) and there's no obvious burn marks on the back. Even if I did mess a 6 pin up, it seems like something that should have come up a lot sooner.
Anyhow, specs are below. Any help would be appreciated.

Motherboard: Z390 Phantom Gaming 4
CPU: I9-9900KF
Storage: Patriot VPN m.2 NVMe 2280 1TB
GPU: Sapphire Nitro+ RT-5700XT
RAM: 2× 8gb DDR4-3600
PSU: Corsair RM750
Cooling: 4x 120mm case fans
CPU Cooling: Deepcool Gammaxx400 w/ 120mm coolermaster fan