How can i fix my Samsung fridge freezer model RSH1NBRS?

The digital readout is flashing but no numbers are shsoingand the temperature of the fridge will not cool, my freezer is working find.
The fridge light works OK but won't go lower than 11 degrees. I also have a build up of ice in the V groove at the back which I don't understand as it's not cold enough to stay frozen.

Is this something I can fix? Don't want to have to buy a new unit especially as the freezer is working fine.

Suesie Q, August 2017

Possibly needs a thorough defrost - fridge and freezer and I think there will be a drain hole in that V grove at the back of the fridge, which may need unblocking - I usually find a length o fthe old fashioned plastic covered net curtain spring wire is useful for that. The manual may tell you more.

Acp, August 2017