I was on my way back from a service call, and received a call from a man asking if we could stop in to give him a price on an A/C unit. I was there in 15 minutes. I took a look at the A/C unit. They had been told by the serviceman that came to clean and check their A/C unit, an old reputable HVAC company, the compressor was burnt out.
I got out my meter, and checked the compressor, and found that it seemed fine. I turned on the power, and it started the A/C unit. The unit started cooling and compression was pumping normally. I had checked the operating pressures, and the unit also required a good cleaning of the condenser as it was covered in lint. I also noticed a capacitor that was leaking oil. I replaced the capacitor, $50, and was about to leave, when the salesman from the company that had told them the compressor was defective, arrived.
I told him that unit is running fine, and he was shocked that one of their service technicians had done this, and apologized.
The customer was very happy not to have to replace their A/C unit. I estimate that it will last at least 10 years, with proper maintenance.