Diagnostics means checking the appliance in sequence instead of replacing parts by guesswork. Power, the door lock, water inlet, drainage, motor, heater, sensors and control board are tested according to the symptom. The aim is to find the primary cause rather than create a temporary restart.
The same error code can have different causes across models. The model, stage where the cycle stops, unusual sound and display code are considered together. The required work, possible part and price are explained before repair begins.