1, the battery of the remote controller should be changed.
The TV remote control uses two No.7 batteries. If the TV remote controller fails, the battery of the remote controller is rarely replaced, so the battery should be tested first.
Solution:
It's caused by the battery, so you need to put on a new battery yourself.
2. The remote control circuit board is broken.
There are two kinds of circuit boards for TV remote control: copper foil and carbon film. When the remote controller falls, it is easy to break the circuit board and open the circuit. If the circuit board is broken, all buttons of the remote control will fail.
Solution:
The TV remote control caused by the circuit board is broken, so a new remote control is needed.
3. The remote control button is broken.
The inner side of the TV remote control button is coated with a layer of conductive rubber, which corresponds to the button contact circuit on the circuit board. When the remote controller is used for a long time, dirt will be attached to the contact point, and the conductive rubber will be aged or worn. The conductive rubber is not conductive and cannot trigger signal coloring, which will lead to the failure of the TV remote controller. Especially, the local key of TV remote controller is invalid, mainly because of the problem of conductive rubber.
Solution:
After disassembling the remote control, find aluminum foil paper to wipe the black conductive rubber and wipe off the dust and other dirty things on the surface.
Paint the contacts of conductive rubber all black with a pencil. The principle is that the main component of rubber and pencil is carbon, and the conductivity is restored.
The infrared LED of the remote controller is broken.
The LED resistance of TV remote controller can only be detected by multimeter.
Solution:
If the LED causes the failure of the TV remote control, only the remote control can be replaced.
5. The crystal oscillator is broken.
General crystal oscillator, used in various circuits, generates oscillation frequency. There are metal shells, glass shells, ceramic or plastic shells.
Solution:
The TV remote controller caused by the crystal oscillator fails and needs to be replaced.
The remote controller mainly relies on integrated circuits (also known as chips) to send instructions. The chip adopts 18 pin dual in-line package (DIP for short).
On the right side of the chip, you can see a diode, a transistor (black with three pins), a vibrator (yellow), two resistors (green) and a capacitor (dark blue). There is also a resistor (green) and a capacitor (small brown disk) next to the battery contact. In this circuit, the chip can detect when the key is pressed.