Quote Originally Posted by Vertigo1 View Post
By ribbed I presume you mean it has some obstruction where the hole is, preventing the clip from fitting correctly? Nothing like that.

The clips are in the bottom most hole and don't seem to want to fit in any others. Might try bending the wires but worried about knackering them completely.
sounds like your bottom ultra fan clip is bent out of shape and might need re-adjustment with needle nose pliers.