One of my identical RAM not working in new motherboard (so weird for me)

[Viktor71]

Hey! I've a weird memory problem with my upgraded PC. I've bought a new motherboard(B450M Pro4) with Ryzen 2600 and one of the previously used RAMs is not working on the new motherboard. (identical memory model)

• 
  ■ I've tried again in the previous MB, it works both in dual and single channel (as well as separately)
  ■ tried the "wrong" ram separately, (tested in every slot)
  ■ updated BIOS to the latest P1.20
  ■ loaded UEFI defaults
  ■ installed a Kingmax 4GB 2400Mhz memory, it worked correctly both in dual channel with the operable Corsair and separately

PC just do not post with the "wrong" one on the new mobo.

I welcome any suggestion what to try next and just thoughts on which one could be wrong the mobo or the memory. Thank you.

Specs:

• 
  ■ Previous CPU: Intel G4560
  New CPU: Ryzen 2600
  ■ Previous MB: B250M Pro4
  New MB: B450M Pro4
  ■ Memory: 2 x Corsair Vengeance LPX 8GB DDR4 2400MHz (CMK8GX4M1A2400C14)
  ■ GPU: Zotac GTX 1050TI Mini
  ■ PSU: Evga 450 B3 (EU)
  ■ SSD: Crucial MX300 275 GB M.2

 

[scout_03]

same os on the hdd for both board you need new os install for the amd board with the working ram first .

 

[Viktor71]

same os on the hdd for both board you need new os install for the amd board with the working ram first .

Unfortunetly I've already done that. Formatted drive and installed WIN10 with the working ram but the mobo do not post still with the other ram installed alone or in dual channel.

 

[scout_03]

memtest her in the old system you could also check on it for any missing connector and if this is not working check with motherboard maker or ram one .