We do live in an area with significant lightning. Probably is the cause of the bad behavior of my TA-624s (multiple over the years).
Can you please elaborate on the surge protectors? Where do I put them, exactly? The TA-624 is plugged into a power supply with surge protection. The phone lines, however, are not on surge protectors. Where (which ends) of the lines would I protect? What surge protectors do you recommend?