A friend's situation is his Track lighting, in a hallway with switches at each end, has stopped working....
Historically only one wall switch worked since moving into the house and only when the opposite end wall switch was in a specific position. Recently a guest flipped the wall switch and the Track lighting no longer works from either end in any combination of positions.
I corrected the misconnected 3 wire cable between the wall switches. One switch had the 2 "travelers " reversed.
With the track lighting transformer disconnected at the ceiling junction box, the wall switches now operated properly, applying power to the disconnected wires.
With track lighting transformer reconnected to both the track and ceiling box power source, the track lights didn't work..
A voltage check at the transformer output confirmed the 12 volt ac but no voltage at any track lights. Light bulbs checked good when removed. Since logic indicates a lack of electrical connection at the 2 conductor bus, contact points were cleaned up but to no avail.
Any help would be appreciated as I'm lost <G>. Thanks, Dick