I had this exact problem when I got a new Wyze Cam Pan. I would not get the ding dong sound when putting in a SD card. The problem is the automatic firmware update does not update correctly. When new out of the box it said there was a new version and I let it update. Then SD card did not work. Tried known good card from another camera, it just corrupts it. Contacted support, they sent me a new camera. I did not update the firmware and it worked fine. Did the update and it was broken. I did a manual firmware update to reload the same new version and now both cameras work fine. Download the firmware on your PC and put on SD card. remember to rename the file to demo.bin Instructions are here: https://support.wyzecam.com/hc/en-us/articles/360041605111-Webcam-Firmware-Instructions