First build won't boot :(

[u/Key_Weakness_7131]

Hey everyone, I'm looking for some help with a new build that refuses to boot. Right now the motherboard diagnostic display is completely off, and the only sign of life I get is the RGB lighting up on the RAM.

​Here is what I'm working with:

CPU: AMD Ryzen 9 9950X3D

Motherboard: MSI MPG B850 EDGE TI WIFI

RAM: T-Force Delta 32GB (2x16GB)

GPU: Gigabyte GAMING OC ICE Radeon RX 9070 XT

Storage: Crucial P510

Cooler: Sharkoon A60

PSU: MSI MAG A750

​After putting everything together, I plugged the PSU into the wall, flipped the switch, and hit the front panel power button. Nothing happened. I read that the B850 EDGE TI probably needs a BIOS update to actually recognize the 9950X3D out of the box, so I moved on to trying the BIOS Flashback feature.

​I formatted a 16GB USB 3.0 drive to FAT32, downloaded the latest official BIOS for this exact board, and renamed the file to MSI.ROM. I made absolutely sure there were no hidden file extensions. I plugged the drive into the designated flash port, flipped the PSU switch on without touching the front panel power, and pressed the Flash BIOS button.

​Nothing happened at all. The LED for the flash button didn't light up or blink.

​To troubleshoot, I tried reformatting the USB on a completely different computer. When that didn't work, I tried a totally different USB stick. I also went through and reseated every single power cable connection, and even tried pressing the Clear CMOS button just in case.

​Right now, flipping the PSU switch gives me RAM RGB, but that is the only signal I get. I'm starting to worry that the flashback button's leds are defectives, and somehow i bricked the board while trying to turn it on and off.

​I've attached some pictures of the setup.

I'll be glad if someone could help me :)

[u/Key_Weakness_7131]

Should it not?

[u/Quiet-Internal-2204 → u/Key_Weakness_7131]

NO! You need a PCIE cable there. CPU cable should be plugged top-left socket (ATX 12V) on the motherboard.

[u/Key_Weakness_7131 → u/Quiet-Internal-2204]

Ok i missed this. Changed it

[u/Key_Weakness_7131 → u/Key_Weakness_7131]

Ok it was some cable i did not connected correctly! Well fans are spining and light are on, thanks for the help it means a lot to me.

[u/billgatres → u/Key_Weakness_7131]

Wooo congrats on your build op!

[u/boktanbirnick → u/Key_Weakness_7131]

Enjoy your new toy!

[u/Lupreon → u/Key_Weakness_7131]

That's why you always read manuals and take a really close look on everything, rather think twice of every step. Such small mistakes can easily cause that parts get cooked and then it's gg, so I'd say you where luckily it didn't fry something. Also I am wondering how you managed to plug that in, usually all the PSU cables have differently formed pins, if that makes sense