I've replaced many selector boards and the problem went away. I'm sure that the board is usually the problem and I feel that on a tac20 the selector board is probably the most sensitive device when it comes to power surges. But I've also replaced selector boards,Checked magnet placement, relearned the hoistway,the problem seemed to go away, but after a week or so there will still be a few selector faults with possible causes that could be related to weak magnets. I would like to know what percentage of selector faults are caused by weak magnets in comparison to bad selector boards as well as bad cpu's. And, is there any advice on testing the strength of a magnet without having to replace.
