Freezer would ice up and refrigerator stop cooling

First i unpluged the power then cleaned everything out of freezer and removed all the drawers and racks them removed the 2 screws at bottem of freezerand removed panel then removed 4 screws on the bulbs and unpluged the wire and took off the sensor and replaced with new one put everthing back. Then on the top of refigerator side on the top behind the adjuster is the defrost timer pulled handle out and off removed plastic shield and removed 2 screws and unplug the timer and change it then put everything back and pluged back in and everything worked in a few minutes