Guangzhou weicai electronic technology Co., Ltd.
High Quality Acf Bonding Machine for TVPanels
This product is used in a variety of FPC, COF, TAB and LCD Panel and PCB combination bonding, is reflected in a variety of sizes LCD vertical, horizontal, vertical band, horizontal belt, black belt, black, colored thread, ribbon , multi-line, black, black and white, vertical half display,horizontal half breakdown maintenance.
Explanation of Common LCD Screen Malfunctions
Fault appearance: vertical line on the screen (black screen)
Fault analysis: The main reasons for vertical lines on the LCD screen are as follows:
1. COF is damaged, the COF chip heats up during the operation of the LCD screen, and the chip pins become loose during long-term operation. The vertical line is usually caused by screens that have been in use for several years; To determine whether the COFIC is loose and causing vertical lines on the screen, we only need to press the position of the COF IC with our fingers. If the vertical lines change, we can preliminarily damage the COF. Replacing the corresponding COF can repair the screen, and it is best to stick a heat sink on the back of the COF after repair to extend its service life.
2. Electrode short circuit. The main cause of electrode short circuit is the short circuit of conductive particles on ACF adhesive, which leads to the appearance of vertical lines. This situation mainly occurs on repaired screens or screens with denser electrodes. 4K screens are more common. To determine this fault, we can set the screen to aging mode; Observe whether there are two or more colors with black lines appearing in the R, G, B states. If so, it is preliminarily judged as an ITO short circuit. Use a microscope to check if there are black spots on the ITO and if there is any accumulation of conductive particles. If so, remove the COF and re bond it
3. ITO circuit breaker, remove COF, check if ITO circuit breaker. This type of fault is mostly caused by liquid inlet. If the vertical line is caused by ITO disconnection, then the bonding COF cannot be repaired. We can only use laser machines for repair.
4. Screen internal short circuit, mainly caused by X-axis power supply to ground short circuit. This type of black wire can only be repaired by cutting open the internal short circuit point with a laser machine.