In my case I thnk the TS1 transceiver issues were becuase of a Image Sensor that wasnt properly communicating/supervising. Both used the 900mhz transceiver, and both reported low signal. Reseated the transceiver, and reset the Image Sensor.
Place system on test
Remove screw on top, Open panel
Unplug battery connector
Unplug AC transformer (wall adapter)
Above cell module is the rectangular transceiver (swiggly antenna) pull it straight out, check pin connections, check antenna/solder, place it back and seat ot firmly, reconnect battery, close panel, reconnect AC
PS the TS1 can use battery backups. (3 AAA) I use rechargeable Energizer/Duracell in mine