Consumer Electronics and Appliances
What this domain tests
Consumer Electronics and Appliances tests the working blocks and common faults of household equipment: refrigerator, washing machine, microwave oven, mixer grinder, fan and remote-controlled appliances. Safety and fault diagnosis are central.
Core rules
- Refrigerator: vapour-compression cycle - compressor, condenser, capillary/expansion device, evaporator. Thermostat switches the compressor; the overload protector protects the motor.
- Washing machine: inlet valve, timer/controller, motor, drain pump and interlocks. A non-spinning drum may be a lid switch, capacitor, belt or controller fault.
- Microwave oven: high-voltage transformer, magnetron, high-voltage capacitor and door interlocks. The capacitor can retain lethal charge after unplugging.
- Mixer grinder: universal motor with speed control; worn carbon brushes or a blown fuse stop it.
- Ceiling/table fan: capacitor-start motor; a humming fan that does not turn often has a failed capacitor or seized bearing.
Worked example
A table fan hums but the blades do not rotate. First isolate power. Turn the shaft by hand: if it is stiff, the bearing is seized and needs cleaning or replacement. If it turns freely, discharge and test the starting capacitor with a capacitance meter; a swollen or open capacitor must be replaced with the same µF and equal or higher voltage rating. Check the supply, switch and winding continuity. The reasoning is that the hum proves power reaches the motor, while no rotation points to starting torque or mechanical load.
Traps
Opening a microwave for diagnosis; assuming a refrigerator needs gas when the fault is the thermostat or compressor start relay; replacing a fan capacitor with a different µF value; and ignoring earthing. Never bypass an interlock or fuse.