Weird things going on with RAM and RAM slots...

[whiteditto]

Okay this one has got me scratching my head a bit...

I have an Asus Z170I Pro Gaming board (mini itx).
It's never been able to run my memory (2x8GB corsair kit) at XMP speeds (2666) - every time I turned on the XMP profile, the system would boot loop for a bit and then show up saying 'Overclocking failed, press F1 to enter setup etc etc.'

Lived with this and not cared for a little bit running on 2133.

Recently took everything apart to clean and the system and on reassembly, it wouldn't post. No diagnostic lights, just appeared to be powering on but never post screening.

Here's the weird bit:
1 Stick (A) in slot A1 will post. 1 Stick (A) in slot B1 WILL NOT post.
1 Stick (B) in slot A1 WILL NOT post. 1 Stick (B) in slot B1 WILL NOT post.
2 Sticks (A) in slot A1 and (B) in B1 will post. 2 Sticks (B)in slot A1 and (A) in B1 WILL NOT post.

Oddly, the 'Stick A in slot A1' will let me turn XMP on and boots fine.

So I'm not sure whether it's the RAM, the board, or a combination of the two. I'm loathed to go through the annoying task of RMA's if I don't have to so any help greatly appreciated.

Thanks

 

[hang-the-9]

When the system boots, check for a BIOS update. Do you have other RAM you can test with? That would probably be the best start.