Question Need some help troubleshooting before I rma motherboard

[i5char]

Parts:
AMD Ryzen 7 2700x
MSI B450 Gaming pro carbon ac atx am4 motherboard
G skill triden z rgb 16gb ddr4-3200 memory
western digital blue 500gb m.2-2280 ssd
seagate barracuda 2tb hdd
evga GeForce rtx 2080 black video card
nzxt - h500 atx mid tower case
evga - super nova g3 650w 80+ gold certified fully-modular atx power supply
monitor- viewsonic xg2402 24" 144hz monitor

Ill try to explain what happened step by step. I put the motherboard on top of the box it came in. I installed the CPU as well as the cooler it came with. I installed the RAM in the slots they were recommended. I tested the parts to see if they worked, by jumping the power switch with a a screwdriver and everything lit up and the fans from the CPU and PSU were spinning. Next I tried testing the parts with the GPU as well as connecting the GPU to a monitor. Everything lit up like before the fans were spinning but I got no signal on the monitor and after like 10-20 seconds everything shut down. I tried to jump the board again but nothing happened. I removed the GPU and tried powering the motherboard on but nothing happened. I tested the PSU with the 24pin connector and the fans spin so I think the PSU is fine. Not sure what to do at this point.

 

[R4DIO4CT1VE]

Yeah thats a little concerning, could be a dead mobo.

Try booting with only one stick of ram (try both individually, i assume you have 2 8gb sticks)
Reset the bios by removing the CMOS battery and wait 5 or so minutes (have the mobo unplugged) and try again to see if it posts.
Make sure you cooler is mounted properly, less of an issue with AMD, but with intel CPU's insufficient mounting pressure can cause issues.

 

[i5char]

Ive tried moving the RAM sticks around and nothing. Removed the cmos battery twice now and still nothing. Im wondering why it was working before and now its not.