Hi my name is ***** ***** first things first is the compressor (motor at the back running) and if you put your hand on it is it hot warm or cold.
OK - bad news Im afraid, the compressor has failed the click you can hear is the safety cut out on the side of the compressor that cuts the electric supply before it overheats. This is a high cost repair, you could be looking at around £300 to replace the motor - I would suggest with the age of the RS20 it not a viable unless you are stuck with it size wise.
Your looking at about £300 all in - you could get it slightly cheaper if you replaced the Samsung compressor with a standard 1/4 horsepower compressor from another manufacturer. We do it here quite often. Samsung compressors are very expensive and in all honesty not to good either. Would you now kindly rate the information given by selecting from the star rating system at the top of the page, once done you can come back to me for further information if needed.