I have 12V AC landscape lighting. Some of the lights are not turning on, so I got one of these 12v AC non-contact testers to try to determine if the cables have been chewed through, etc.: https://www.homedepot.com/p/Klein-Tools-12-Volt-to-1000-Volt-AV-Dual-Range-Non-Contact-Voltage-Tester-NCVT-2PR/312649969?cm_mmc=ecc-_-THD_THANKYOU-_-V1_M1_CA-_-Product_URL&ecc_ord=W878088347&em_id=60b46fbe3a00a750b6b15514e556881a8d75050aa0be1f6cf69d349fac9c8867
However, even on some of the cables that are working, the device doesn't alarm (when used following the user manual and on 12v mode). I read that this could happen when the cables are shielded. Assuming this is the case, what is one to do? I didn't have any luck searching for similar devices that work with shielded cables.