ram slots a1 a2 not working - ASUS ROG MAXIMUS Z790 APEX ENCORE LGA 1700 ... bs888 slot

On booting the PC, I discovered that both B1 and B2 RAM slots were not working. PC doesn't boot if I put RAM on either B1 or B2 slot.

Hi, I have bought Asrock Xtreme 11 motherboard with 'Gskill Trident X F3-2400C10Q-32GTX RAM'. mobo has 8 dimm slots namely a1,a2,b1,b2,c1,c2,d1,d2. The problem is c1 is not working. I checked individual ram sticks and they are working perfectly. But whenever i insert any stick into c1, it is...

GA-H81M-S BOTH RAM SLOTS NOT WORKING, ERROR CODE ".

Apparently, I put the sticks in the A1/B1 DImm slots and I was supposed to put it in the A2/B2 slots. after correcting that mistake, my ram worked perfectly ...