Modern monitors are of a fairly high quality and are capable of working properly for more than one year. However, sometimes they do fail. The easiest way is to take your faulty monitor to a workshop, but you can try to repair it yourself.
Instructions
Step 1
If a monitor with a cathode-ray tube fails, the nature of the malfunction should be assessed. The monitor may show no signs of life at all, it may turn on, but the screen remains dark. Finally, image distortion may appear.
Step 2
In the first case, check if the monitor is receiving power. If the power cord is OK, check the power button. Next, you need to check the power supply, for this you will need to measure the output voltages with a tester. They must correspond to the voltages indicated in the circuit diagram. Find the scheme on the Internet.
Step 3
In the absence of any voltage, look for a malfunction in the corresponding section of the power supply unit or in the consumers of this voltage. Check fuses. In modern monitors, instead of fuses with a glass case, there are small ceramic fuses that look like the MLT-0, 125 resistor. Look for their location according to the diagram and by the designations on the back of the board.
Step 4
If the power indicator is on, but the screen remains dark and you do not hear the characteristic crackling that occurs when a high voltage appears on the anode of the CRT, check the line scanner. Pay attention to the correspondence of the measured voltages to those indicated on the test points of the circuit.
Step 5
It is possible that a narrow bright horizontal stripe is visible in the center of the screen - this is a sign of a faulty frame scan. If there is an image, but it is too narrow vertically, the cause of the malfunction must also be looked for in the vertical scan. Most likely, one of the capacitors is to blame.
Step 6
The possibility of self-repair of the LCD monitor depends on the severity of the breakdown. If the image disappears, turn off the light in the room and shine a flashlight on the monitor - you may see a very faint image. This means that the backlight does not work. The most common cause of such a malfunction is the broken capacitors of the power supply.
Step 7
To disassemble the monitor, unplug it, remove the “leg”, lay the screen down on a soft pad. To open the case, you will need a suitable tool: an unnecessary telephone card, a plastic tab for playing guitar, or something similar. Insert the edge of the card into the joint between the top and bottom of the monitor and try to separate them - they are connected by internal latches. The latch will open with a loud crash. Walking around the perimeter of the monitor, separate all latches and separate the panels.
Step 8
Now, carefully get to the board, for this you will need to disconnect several connectors and unscrew the screws. Look for swollen capacitors on the board, they are usually clearly visible. In serviceable ones, the top is flat, in unfit ones, it is swollen. Replace them with new ones. Be sure to check the fuse, when a capacitor breaks down, it usually burns out. After replacing the defective parts, reassemble the monitor and turn it on without closing the back cover.
Step 9
If the image appears, then everything is in order and the monitor can be assembled to the end. If not, the inverter microcircuit may be punctured, other reasons are also possible. In this case, it would be more correct to carefully assemble the monitor and take it to the workshop - without proper knowledge, it will be very difficult to repair it yourself. Alternatively, search online forums for information on malfunctions specific to your monitor model.
