3-way HAI switch seems to have gone bad - help needed

[bodonnell]

Couple things here. You're likely looking at a "remote" switch from your description as one of the other posters mentioned. I'm pretty sure Leviton and/or HAI had these available, I know PCS does. They're a hard wired remote switch that connects to the yellow wire. Its helpful if you specify the brand and part number of the switch. The first thing you might want to look at is how those connections are in the boxes in the wall. Are the wire nuts tight. ITs possible they're just worn out or damaged. I have my clients put a full house surge suppressor in as a prerequisite for an automation install. ITs not a guarantee, but its silly to install thousands or tens of thousands of dollars of electronic equipment and have it exposed "naked" on the grid. Back to your question - you have access to turn the lights on/off - that's good. At least "something" works. Just troubleshoot what doesn't. I would look at the physical connections of all 3 switches. Make sure you or someone else hasn't put a sheetrock screw through a wire recently causing an issue. Then, failing that, I would find replacement switches (remotes) on eBay or one of the distributor sites. I wouldn't "cross-pollinate" - stick with the same part number/manufacturer or replace all 3 with a newer part. Stick with new products. A 15 year old switch in a box works just as well today as it did 15 years ago. NOS (New Old Stock) is a great way to save money. If you report back your findings I'll try to follow up, though I'm not on here a lot.