Check if the switch socket is faulty?

Update:05-07-2019
Summary:

When our electrical appliances fail, the first thing we […]

When our electrical appliances fail, the first thing we suspect is the failure of the internal parts. For example, is the outlet of the socket normal, the connector is normal, and the connector is normal. If it is judged to be faulty? We can judge by the following four simple methods:
1. The first is to see
Use your eyes to observe whether the various switches, buttons and knobs of the appliance are placed in the correct position, whether there is any lack or damage, whether the display and indicator on the display are normal, and whether the appearance of the machine is damaged. Disassemble the appliance and check if the internal connectors and wiring are disconnected or loose, and the printed circuit board is broken or damaged. Components such as resistors, capacitors, transistors, and integrated blocks are burnt, burst, missing or broken, and desoldered. Whether the sensors, detection lamps, adjustment switches, etc. are damaged or displaced. Whether the drive belt and gears are deformed, aged or fallen off. Whether the belt mechanism, transmission link, etc. are displaced, deformed and damaged, and whether the moving parts are flexible. After the power-on test, there is no fire or smoke in the machine. Whether the head is broken or not clean.
2. Nasal smell
Use your nose to smell if there is any burnt or other odor in the appliance.
3. Listen
Shake the appliance and shake it to see if there are any loose or falling parts in the machine.
4. Manual
Gently pull the relevant wires, plugs, sockets and components by hand to see if they fall off. Pull the relevant parts and try to tighten the tightness and flexibility. After power-on, touch the power transformer, adjustment tube, manifold or other related components to see if there is any overheating.