I've used Collar Clinic for rebuilds and Gun Dog Supply for parts with a lot of satisfaction. The second generation units I had had one transmitter not take a charge and one receiver the same. I replaced the batteries in both units and had the receiver start working but the transmitter is still inoperative.
That started my dissatisfaction with TT and was sealed with the Garmin unit. I would probably go with Sportdog over TT these days.
