Question Dimm slots not working others work

[abdulfire97]

I have a new motherboard and I had it sitting on the box using it that way while waiting for the case it ran fine the dimm slots worked. Once the case arrived I got everything in to the case in a big struggle. Once I got the motherboard in I tested it to make sure everything worked(I've been having bad luck with motherboards lately) I got into to bios fine so everything works. I finished the build in a struggle. I turned it on it wouldn't post gpu fans were at 100 after playing around and doing a bios flash a few time (instead taking cmos out not ideal but it was a struggle to build this)dimm slot 3 and 4 will not let the computer post 1 and 2 work and the computer runs flawlessly (in single channel of course) I tried running soly dimm 4 to see if the CPU had a issue but same result no post I was hoping to see if anyone had advice
thanks
The motherboard is Asus ROG Stirix b450f 2

 

[abdulfire97]

The only thing I can think of is it fell on the table during build if that damaged anything