Why does one stick of RAM refuse to work when installed with others?

Question

Iron

Bought 32Gb DDR4 2666MHz Crucial Ballistix Red (BL2K16G26C16U4R) (2x16 KIT) - 2 pcs. A total of 4 sticks of 16 GB each.
One of the bars refuses to work together with others - the bios is stupidly not loaded, and the red light is on on the mother (asus tuf h370 pro gaming) .. If you stick only this one bar, then okay. I noticed that three of them have the same part number, but this one is different. Can this really lead to their incompatibility?

Answer 1

through aida64 (if you use Windows) look at the information about
the bars if this bar has exactly the same parameters (supported frequency / timings), that is, the risk of a defective batch
if the parameters are different, then hand it over without warranty questions at all - they threw you a bar of another model with a re-glued sticker
when buying two identical kits of strips, they must all be compatible with each other
PS: sometimes resetting CMOS / BIOS solves phantom bugs

Answer 2

1) Open the Qualified Vendor List for memory
https://www.asus.com/en/Motherboards/TUF-H370-PRO-...
2) See which 16 GB modules are marked 4 DIMMs.
3) Buy just such, rejoice that everything works.
The compatibility list is limited, but this does not mean that modules that are not on this list will not work with MP. They can earn, or they can, as in this case, not.

Answer 3

you put one / all / the same bars (in which the minimum frequency and the maximum timings of those that you have)
reboot you
go into the BIOS
uncheck the automatic settings (regarding the memory settings)
reboot
install another die (other bars)
again reboot
PS
BIOS automatically reads the profile , with which these brackets cannot work in tandem,
you need to set the minimum with the handles , and not the one that is flashed in the spd | xpm profile PS if there is
a
glitch / failure = reset the BIOS and repeat everything
from the beginning ddr3 is not ddr2 = here it is much easier with compatibility
will/should operate at minimum frequency