The customer is having difficulty installing Dell ReadyRails II into a NetShelter cabinet.
NetShelter SX, VX, SV, CX
All versions and serial ranges.
The rails are loose and fall off.
The ReadyRails II has rounded pins that are made to fit into the older Dell cabinets with round holes in the vertical rails. NetShelter cabinets do not have these round holes, they have standard EIA/ECA-310-E square holes.
The ReadyRails II will fit into the square holes of the NetShelter cabinet. After inserting the round pegs of the ReadyRails II into the square hole if the NetShelter cabinet, push firmly on the ReadyRails II. The ReadyRails have a square feature that will seat firmly into the square hole in the NetShelter's vertical mounting rail.
It's also possible that the Dell ReadyRails is not set deep enough. If you attempt to install the ReadyRails II in a position that's shallower then the minimum mounting depth called out by Dell, it's possible the rail will not seat firmly. You may have to increase the distance between the vertical mounting rails until it's within the maufacturer's specified mounting depth.