The LCD TV replaced the CRT — kinescope relatively recently. Functional, low power consumption, and no harmful radiation, such LED and LCD arrays have become popular among electronic devices and have almost replaced obsolete devices that use CRTs. However, novelties also break. Various malfunctions of TVs are not uncommon, including breakdowns of LCD matrices. In this connection, they require replacement or timely repair. Replacement or repair of the LCD matrix can be done by hand.
The principle of operation of the LCD matrix
An LCD matrix is a working surface made of glass with several million pixels; they change color, as well as the brightness of their glow due to the influence of external control signals. Matrix pixels form the image that we see.
Chips are used to control some pixels. Chips are called drivers that control signals that send a specific signal for each pixel. Usually, control drivers are located on flexible cables soldered into the very base of the matrix glass. This loop cannot be separated from the glass, it will also not be possible to replace one loop. In addition, it contains driver power supplies, as well as decoder microcircuits.
See also - How to repair a TV with your own hands
Matrix breakdowns can be conditionally divided into the following groups:
- Mechanical violations (bends of matrices, water penetration, impact).
- Breakdown of microcircuits and other parts (resistor, diodes, capacitor, inductance) that ensure the constant operability of these microcircuits that form the image. They are on a flexible non-removable cable.
- Violation of a non-removable loop
- “Burn-in” of pixels that are no longer functional without a mechanical justification.
- Backlight not working
The malfunctions of the matrices described above lead to their replacement, since repairs will be too expensive or simply impossible. Replacement in this case is a priority option. For example, the backlight inverter for fluorescent lamps is often located on the power supply board, while the lamps are also easy to replace. It is more difficult with malfunctions in the operation of LED backlights, usually the manufacturer makes it control on flexible indelible cables. However, here you can try to make repairs with your own hands.
Disassembly of a TV with a front housing system
The principle of replacing the matrix depends on the TV model, manufacturer, as well as the dimensions of the matrix. However, there are general rules. There are two popular types of case fastening — these are screw connections and plastic latches.
The front panel of the cladding must be wrung out and the latches removed. Then you will see a matrix screwed to the main body of the TV using metal screws or screws. It is necessary to unscrew each mount and separate it. Be careful — perhaps the screws are duplicated with latches. It will also be necessary to dismantle the bolts on the back of the TV, they fasten the case to a metal screen that provides protection against malfunctions of the power supply, as well as the control board.
When everything is done as it should, the matrix with all the electronics should be separated from the case. In order to prevent chips and scratches, it is recommended to place the element on a soft fabric, flannel is perfect for this. Next, disconnect the panel from the connecting cable, be extremely careful. In some situations, for additional fastening, as well as protection against cable shift, the manufacturer glues strips of adhesive tape to the connection.
Carefully remove it, lift the clip — the dog located on the connector, for this you can take small tweezers. In order not to damage narrow paths, you need to try to get the cable without swinging it in different directions. Then you need to remove the stiffness panel from the matrix. To this end, we unscrew the screws from the ends, for various manufacturers they can be in the amount of 2 — 12 pieces on one side.
Dismantling the matrix with rear disassembly
This repair has a similar order, except that there is no front facing television frame, but this is partly the case, since there are quite a few models, so there are certain technological subtleties. In the future, the analysis of the control board, as well as the basis for the rigidity of the matrices, is identical. The matrix is mounted in the reverse order
When performing these operations, you can make a hint. If for the first time you decide to replace the matrix with your own hands, then it is recommended to record the actions with the help of a camera. On this, in principle, everything. Remember and follow safety precautions, and carefully follow each step when repairing or replacing matrices of a plasma or LCD TV.