Mobo Only Sees One Stick Of RAM

[wunder]

Brand new build is working fine, so haven't noticed that only 8gb of my 16gb is recognised by the mother board (Asus Prime Z270 - P) for a few days.

The two sticks of RAM are in DIMM_A2 and DIMM_B2 as per manual, found here:

http://dlcdnet.asus.com/pub/ASUS/mb/LGA1151/PRIME_Z270-P/E12008_PRIME_Z270-P_UM_web_only_20170712.pdf

I have tried swapping them around, but it will not boot.
The only slot that will boot is if the stick that was originally in A2 is in A2.
If the stick that was in B2 is in A2 it will not start, this suggests that that individual stick is faulty, no?

I'm a bit confused by the good stick of RAM not booting up in another slot, it should work in anyone shouldn't it?

Thanks in advance for any assistance.

 

[DRagor]

If the stick that was in B2 is in A2 it will not start, this suggests that that individual stick is faulty, no?

Yes, it would look like so.

I'm a bit confused by the good stick of RAM not booting up in another slot, it should work in anyone shouldn't it?

It should, but some motherboards are a bit more picky about it. If motherboard manual tells exactly, which slot to use in case of using only single stick, chance are it won't boot with stick in other slot, as seems to be your case.

I.m assuming you bought both sticks as single kit - in such case you should RMA whole kit. Unless you have access to additional sticks of ram to make further tests.