I checked CPU pins and also tried with  new DRAM sticks (Corsair Vengeance 2x8GB 3600Mhz). Unfortunately Channel B remains non functional. If there is a stick in any B channel slot booting does not proceed and orange error light remains next to DRAM ...

Thanks! Very good info to me that you have tried with different CPUs and memory stick models.I had the same problem also with Ryzen 5 1600 and some 2017 BIOS model back then. Same HyperX sticks.The main motivator to me is to get dual channel working....

Hi!Funny that you posted about this right now.  I have exactly the same problem. I have been investigating that for a few days now and some days seven years ago when I bought the motherboard.Current setup:- Asus ROG STRIX 350-F with latest BIOS- AMD...