In our lives, bright LCD screens are everywhere. During the use of the LCD screen, there may be problems, so in order to repair the LCD screen, it is necessary to learn to determine which part is faulty. Let's take LCD TV as an example to talk about common faults and their location judgments on LCD screens.
1. When starting up, there is no image or sound, the power light flashes and becomes constantly on, and the screen flashes white light instantly. This fault is mostly caused by a damaged backlight driver board. However, it has also been encountered during maintenance that the light tube inside the screen is damaged.
2. After turning on for a while, there is a mosaic screen, and the sound is normal. The first reason for this phenomenon is that the digital board is poor (the via is not connected or the IC is not in good contact). The second reason is that the internal wiring of the machine is not in good contact.
3. Power on with three no's, the power light is not on. The first one is that the power board is broken, and the second one is that the CPU is not working properly.
4. Flashing lights cannot power on, CPU bus is not working properly or the boot program IC (BIOS) is poor, and there is poor contact between the BIOS IC and the CPU.
Next, let's talk about the frequently encountered high brightness LCD screen machines and their fault phenomena and troubleshooting methods
1. The problems with LCD screens (black stripes, bright lines) are the most common, and this situation is generally not possible without maintenance conditions, only relying on technical and maintenance conditions.
2. The buffering board of the screen component of the LG V6 V7 is a common problem due to full screen clutter, and some are regular vertical bars with full screen. This type of fault can be replaced with a pair of buffering boards (even if one side is damaged, buy a pair. They won't sell a single one to you) or measure which IC is faulty and replace it.
3. Regardless of the type of LCD screen, the Y-board is the second most likely to break in PDP machines. After it is damaged, the phenomenon is usually a blurred screen, full screen color dots, or power protection caused by short circuits. VS or VA voltage may appear instantly, but cannot reach the voltage value indicated on the screen.
4. The X board is also a common component in PDP machines, characterized by power on protection (Fujitsu screens are more common) and low brightness.
5. The failure rate of logic boards is also not low, which is quite common in PDP LCDs. Its performance is mostly that the screen has light, but there may be no characters, no images, or irregular color disorder, missing colors, negative images, etc. Some cannot be turned on yet.
6. The common problems with LCD screens are dark bands and lines, which are the most common. These can be summarized as LCD screen problems. Some require maintenance conditions to repair, while others are caused by high temperatures that cause the COF and ACF at the connection point of the LCD screen to detach. This phenomenon can be repaired by using a flat headed soldering iron to heat up the insulation medium under the cushion layer.
7. In LCD machines, the inverter circuit (high-voltage board) of the screen component is a frequently faulty component, which appears as having light when turned on but then no light but sound after a while, except for SHARP. However, aging and damage to the light tube can cause protection for the high-voltage board. The method to determine whether the light tube or the high-voltage board itself is damaged is to cancel the average comparison feedback circuit on the high-voltage board.
8. Many friends often ask how to repair SHARP's LCD, but in fact, it is similar to a regular LCD. After entering the repair menu, you can see that there is a fault code in the error item. Some directly reset the code, while others need to repair the corresponding fault area.
Ruxin Gaoliang is committed to creating long-term value for our customers. We are a high-quality domestic LCD display manufacturer with 13 years of experience in research, development, production, and sales, specializing in various types such as high brightness screens, bar screens, and small-sized LCD screens. We provide one-on-one professional services for you.