New
#361
As best as you can make sure the slot and the cross bars in the bottom of the slot have no extra pieces of plastic in the way.
I had a RAM slot that wouldn't let the stick seat properly on this ASUS board.
When I looked closely and compared it to a slot that did work it had a tiny piece of plastic in that one slot left over from the molding process.
Xacto knife trimmed it and no more problem.
It was very small piece of plastic but in the tight slots that was all that was needed. This- * - was bigger than that extra piece was.
If like me clean your reading glasses and drag out the magnifying glass.