Question Asus Strix B350F and RX 6650XT not compatible ?

Nov 9, 2022
Just bought a RX 6650XT (to replace my R9 380gb) to go with My :

MB asus strix b350f
CPU Ryzen 5 1600
Ram 32gb ddr4
PSU 650W Cooler M.
Win10 64

and.... no post ( ''No input suported'') on screen. But ! I can hear my pc powering/loading up normaly... so I plug in my tv and then I get an image but in device manager, my pc can't see my new gpu, only on board. Then I unplug hdmi cable from tv to put in my Acer pc screen and Voila ! I got the image. So I go get the drivers for my new gpu and my system can finally see it ! I restart and... back to no post. While trouble shooting this , I tried my old gpu in and every time no issues. I read a lot about it and start to think that there is compatibility issue since my MB PCIe are 3.0 and new GPU are 4.0. Suppose to to work in each others but Could it be possible that 3.0 are ok in 4.0 but the opposite could be problematic ? Thanks for info :)