Broken GE Dimmer Switch - passing voltage to Traveler and Neutral

TL;DR - a previously good switch is now unresponsive and showing voltage (High enough to be detected using voltage tester) on both the traveler and the neutral terminals even with nothing attached. Is my switch toast? Is my add-on switch toast by association?

I was repurposing a previously rock-solid GE/Jasco ZW3005 (12724) working as a 2way light switch to a different location as a 3-way switch along with a newly purchased add on switch. After a series of experiments I was fairly confident that my wiring topology matched the example that came with the add on switch and I wired accordingly, but when I juiced it up, there was darkness - no blue LED, no response to button pushes. This is when I poked around and found Load low, Line hot, Traveler and Neutral Hot

I shut off at the breaker and debugged tot he point where I isolated the source of the power to Neutral/Traveler connection to be within the dimmer switch (removing wires from traveler and neutral still shows voltage at the empty terminals). I didn’t have a multimeter handy and I’m not sure what the threshold of my voltage tester is for lighting up, so, I can’t be certain we see the full 120V at the terminals, but there’s something there…

Swapping in a 2-way (spst) switch where the dimmer was, using the black traveler line as a passthrough to the load and leaving the Red traveler empty (I think) confirms that my analysis of existing wiring was correct.

Anyone have any insight into what is toast, what is recoverable and what I messed up?

Thanks all!

Did you measure the voltage on the neutral terminal while the neutral was connected? If so, that’s a strong indication that the neutral wire you connected isn’t actually connected to neutral at the breaker box.

If the neutral terminal was not connected, well, then I don’t really know, but I’d say measuring some voltage in that case isn’t a strong indication that something is broken.

Hi KG - I did check with the voltage tester while both Traveler and Neutral were connected as well as with both disconnected, but did not have a multimeter handy when I was debugging, unfortunately. To add to indications of broken-ness, I reinstalled in its original application and it no longer works there either. When I get some free time (and someone to keep the kiddos out of the way) I’ll try to get a less binary voltage reading at the Neutral and Traveler terminals and report.

thanks for your suggestions!

I think the switch is toasted because your wiring is not what you think it is and supplied full voltage to the traveler terminal. This damaged the switch. I would double check your wiring again. And test the switch by just hooking up line hot, neutral first. As for what can be recovered. Give jasco a call. They have excellent customer service.