Fridge freezer compressors what can go wrong with them , common failure issues

So what can go wrong with compressors , well they can a do fail they can fail electrically and mechanically but sometimes the control side of things can fail so ensure you are 100% correct when condemning and replacing a compressor as they are expensive and difficult to replace.

The pistons in these compressor sit in a bath of oil that what makes them so reliable obviously a loss of oil would cause failure quite rapidly even seizure of the entire compressor. A seized compressor can still be attempting to start and this can be heard as a clicking this is the relay and overload protection attempting to start the compressor then cutting out when it cannot and it shuts power off.

Over time seals can wear and reduce the pumps efficiency sometimes you can tap on a compressor and it will alter the pressure reading this is a symptom of bad seals. 

Windings can fail open or shorted so measuring these correctly depending on the type of compressor is very important. When testing a normal compressor the 2 start run winding reading should equal the final measurement.  when testing invertor winding they all should be equal and the LG linear invertor compressor only has one measurable winding between 4-9 ohms.