Samsung TVs have a good value for money, therefore they are well-deservedly popular. Nevertheless, even very reliable models sometimes fail. If you can read circuit diagrams, use measuring equipment and hold a soldering iron in your hands, try repairing the TV yourself.
Instructions
Step 1
A modern TV is a complex electronic device that can be easily damaged if improperly repaired. That is why do all the work very carefully, never using force. Remember that repairing LCD TVs is often associated with the need to restore software, which is difficult to do on your own. Therefore, at home, it is better to limit yourself to repairing TVs with a CRT monitor (with a cathode ray tube).
Step 2
The most common malfunctions of Samsung TVs are the failure of the power supply and the SSB (Central Control Board) board. If the TV shows no signs of life, first check the power supply to the outlet. Then remove the back cover of the TV, check the power cord and the power button.
Step 3
In the event that the mains voltage is properly supplied to the TV, you should check the power supply. Examine its board carefully, pay attention to any signs of overheating. As a rule, capacitors in the power supply most often fail, the faulty ones are easy enough to identify by the swollen top - in a serviceable part it is flat.
Step 4
If visual inspection does not lead to a malfunction, check the output voltages. You will need a schematic diagram of your TV; find it on the internet. The diagram shows all the output voltages of the power supply. Most often, there is no line scan supply voltage; it should be around 110-160 volts, depending on the size of the screen. The larger it is, the higher the voltage.
Step 5
Now you need to understand why there is no output voltage: the power supply is faulty or the fault should be looked for in the line scan unit. Disconnect the 110-160 V output voltage from the scanner, for which you may need to unsolder one of the parts of the power supply. Now connect an ordinary incandescent lamp with a power of about 100 watts as a load. Turn on the TV and measure the voltage across the lamp. If it is close to normal, the power supply is working.
Step 6
Check the line scan circuits. Pay attention to the health of diodes and transistors. Start testing the transistor without unsoldering it. In the event that the tester shows a breakdown, you should unsolder the transistor or unsolder the conductors going to it (it is enough to unsolder two) and check again.
Step 7
The same principle applies to diodes as well - unsolder one of the leads only if the tester shows a breakdown. Use a pointer multimeter. It is much more informative than digital - the serviceability of parts can be judged by the degree of deflection of the arrow, its throw at the moment of connection, etc.
Step 8
If the TV turns on, but a narrow horizontal stripe is visible on the screen, the vertical scanning module is faulty. Check its details; for microcircuits, pay attention to the correspondence of the voltages at their terminals to those indicated in the diagram.
Step 9
If the LSD TV loses picture, darken the room and shine a flashlight on the screen. If you see a faint image, the power supply may be defective. Check the power filter capacitors; most often they are the ones that fail. If they are faulty, be sure to check the fuse installed on the board; it usually burns out. Replace defective parts and turn on the TV. If the image does not appear, the inverter is most likely defective. Replace the defective microcircuit.
