The compressor is working on our Fisher Paykel E522B- the lower freezer can maintain -15degC but the upper refrigerator section doesn't fall below 7-8degC nomatter what setting on Smart control. Do I need to replace the smart thermostat control and if so, can you suggest source for parts and advise on repair method? Regards Greg Mann

Hi Greg,
Before you replace Thermostat control, please try the below steps:
Things You'll Need:
Screwdriver
Volt-Ohm Multi-tester
Notebook
Pencil
Flashlight

Step 1 Check the easiest and most common potential causes first, which is the best course of action in any troubleshooting case. With a freezing refrigerator, this means checking the thermostat itself to see if it is set at the right temperature.
Sometimes, other family members may accidentally turn the dial, so just make sure that the dial is not turned to the coldest setting. If the setting is correct and you are still having your foods frozen, then you may have to troubleshoot the workings of the thermostat.
Step 2 Unplug your refrigerator. Next, locate the control panel where the thermostat is located and remove all of the items near it so you can work.
The thermostat is located directly behind the dial. You may need the flashlight to help you see inside the refrigerator.
Step 3 Remove the plastic cover that protects the controls. Some covers are screwed into place while others are held in place by plastic clips. Depending on your make and model refrigerator, you may have to first remove the dial before you can take the cover off.
Step 4 Turn the dial to the coldest setting. Remove the two leads (wires) on the thermostat.
Note: It helps to write down which lead goes where for when it's time to replace everything.
Step 5 Set the volt-ohm multimeter to RX1 and probe the terminals. By "probe," I mean touch one of the multimeter's probes to one terminal on the thermostat and the other probe to the other terminal.
You should be getting a reading of zero. If you get a zero reading, then move on to Step 6. If you do not get a zero reading, then remove the thermostat and take it to an appliance store for a replacement.
Step 6 Remove the thermostat from the refrigerator entirely. Set the dial on the thermostat to the warmest setting and place the thermostat in a working freezer for 30 minutes.
After the 30 minutes are up, reprobe the terminals and look for a reading of infinity. If you get the infinity reading, then the thermostat is fine. Simply reinstall it, plug the refrigerator back in and look for another cause of your freezing problem, like dirty coils.
If you do not get an infinity reading (sideways "eight"), you should replace the thermostat with a new one.
I also advise you to visit the below link:
http://www.ehow.com/how_2167621_troubleshoot-refrigerators-thermostat.html