I called a technician for no cooling. He came and diagonsed and concluded that the relay and overload protector is faulty. Replaced it charged me 1200(incl) and after two days the fridge stopped working. Unfortunately I had an emergency to leave out of town. After 10 days I called for the same complaint. They sent the same technician and now he said compressor is burnt and the new relay and overload is also burnt.
I raised my complaint, they sent another technician who concluded that the first technician did proper work.
By profession I am also in the same field and understand the mechanism. The new relay and overload will not burn again and again. Improper Diagonisis and temporary repairs led to the compressor failure.
This is how they cheat people. When asked for a solution they gave and answer that it's a new job and new charge work. more
As you are from the same field it would be easier to diagnose and understand. You can use a multimeter to check the faulty components yourself. A fridge does not have many too many components and most of them are on the outside only. You can easily check them. You have not mentioned how old is the refrigerator.
You also need to check for the refrigerant gas level if the compressor is ok but it is not cooling.
Most of the service center guys cheat the unsuspecting customers by claiming that more than one part has failed (which might not be true) and then replace all of them one after the other.
Most often both relay and overload protector do not burn out together and only one of them fails (mostly relay) but as a precaution it is recommended to change both of them (but not mandatory).
I am an electronics engineer and I repair all my household electric / electronic / mechanical gadgets myself. more
These service providers do not engage qualified technicians to save money and their employees without any technical knowledge only misguide the households to cheat. I had an occasion last year as regards to a window AC to experience such a situation giving an estimate of Rs.10,000/- for replacement of the compressor. My sixth sense worked and I asked them to decide later and called a private service provider. The boy deputed by him had changed a condenser of the AC and the machine started functioning nicely. The job costed only a meagre amount of Rs.500.00 only. As such, you may also try your luck prior to replacing the compressor for several thousand of rupees. more