My refrigerator is on but isn't cooling...please help!

by Mr.Weis Salameh
(Doha-Qatar)

My refrigerator coils get hot but it doesn't cool the food inside, what is the problem?

The compressor works properly but inside the fridge is not cold enough.

Is this a refrigerator repair I can do myself or do I need to hire someone?

Thank you very much for your help.