Hello My name is Ian ~ I am not on the site constantly so please be patient whilst waiting for responses to you queries
Firstly the segment in the display indicates that there is a refrigerator defrost sensor fault and this will need checking out. To reset the unit press the top left and the top right buttons in the display and wait for the display to flash and then go blank. Then let go of the buttons and see if the display relights.
Hello Im here
I have done as you have requested and that appears to have worked well. The temperature settings have re-appeared
I will make a note of this for future reference should the power need to be turned off again
Ian, just one more question after reading your response again. Do I still need an engineer to check out the sensor?