I have a Polar brand CS100 Heart Rate Monitor that I use when exercising. During the weekend it started flashing to say the battery needed replacing. Replaced it with the correct type of 3v button battery and it appeared that the whole thing had packed up. There was stuff on the display but it was meaningless.
A new unit is $200 which I would prefer not to pay. Rang the agents and service people, Brittain Wynyard, and they said bring it in. They checked it and said that, although it was well out of warranty period (2005 model), it should not have failed like that when a new battery was put in, so they replaced the circuit board, free of charge. Then they checked and pressure-tested etc to make sure it was OK. The whole thing at BW took less than 10 minutes.
Just want to give BW credit. Great way to develop customer loyalty to a brand. I was rapt.