Samsung SR519DP, temp varies between 3 and 10

temp too warm if temp is ok by checking with thermometer then replace temp sensor

call a good local repair service second hand is never a good choice .assume you are down under as it is still july 1 here

correct

The compressor probably needs re-gasing. You will need a refrigeration engineer.

Good luck

have alook at this samsung fridge freezer channel on youtube



some good stuff re common samsung fridge freezer faults ">

There may be a fan that moves cold air in the freezer and icemaker compartment(s).  If the fan freezes up the cold air will not circulate.  Since the fridge compartment is still cold it does not sound like a compressor problem.

Is the evap fan running? What is the current temp and how long has the unit been in operation

It seems it's the defrost sensor (freezer side). Waiting for it to come, ordered this morning. It appears to be a defrost fault, having read on the web it seems you can check the defrost sensor with a meter across whilst holding the actual sensor in your hand tightly to see if the resistance changes, anyway it didn't. Will post when the new one comes and I change it.

you can reset the fridge by pushing "Power Freeze" and "Power cool" at the same time

it worked with my fridge Samsung RS21DAMS which stopped after a power cut and was also flashing at the digit of the fridge temp display

Based on your weird display issues I'd lean toward the control board problem. At least that can be "one" of a couple problems...