Freezer Defrost Heater

Hi my refrigerator is having problem.Freezer is ok but the Fridge part is not cool.Again i m throwing the water on the eveporator and it works fine up to three days.But again ice formation starts and there is no cooling on the fridge section.Technition told me that there may b a fault in the Electronic controll panel but he said that the heater is ok.He did not check the thermostat but he said that these r ok generally.Now this electronic panel is not available here in dubai.And i dont want to throw it.I want to change the wiring by fixing timer and other parts and this i want to do myself.Please if any body know about the diagram or he can send me useful information please let me know.If i can get the IC of controll panel then it is very good but i dont know from where?.Please help me and send me the diagram or tell me where can i find this

Thanks