Common four tips for touch screen repair

- Nov 13, 2019-

In today's society, touch screens are used in many electronic products, and they are also popular among consumers. In our home life, there may be a friend's home TV is a touch screen. It's as easy as playing a mobile phone, but I have to say that when the mobile phone has a bad screen, the touch screen is the same. Then what happens to the touch screen, how to repair the touch screen?


Touch screen repair case one:


Siemens touch screen repair TP270 Fault phenomenon: power supply DC 24 volts, no light on the screen, current about 230 mA Processing: Touch the screen by hand, the buzzer echoes, clarify that the program is running normally. The high voltage strip 12 volt DC voltage is normal, the control voltage ENABLE low is useful for low level normal. Clarify that the fault in the high-voltage episode circuit or tube is now damaged. After disassembling, it was found that the lamp was black, and there was still no light after replacing the lamp. The high voltage transformer was also damaged. There is no such high-voltage transformer on the market, so I buy an LCD high-voltage strip with two tubes. After connecting the line, it is fixed and the power is normal.


Touch screen maintenance case 2:


Haitek contact panel repair PWS500 Fault phenomenon: no screen is displayed after power-on, current is about 100mA. Correction process: Touch the screen by hand, the buzzer does not respond, and clarify that the program is not working properly. The multimeter measures several sets of voltages of 3.3 volts, 5.1 volts, and 12 volts. According to the user's report, the user found that after the contact screen was faulty, he tried to repair it. In the process of power-on, he showed a normal condition, but after power-off, it will not work again. Analyze the chip to have a solder joint on one of the pins, making the bus faulty, and then the program can not run.加热 Heat the soldering foot of the dense chip with a heat gun, and press the chip with tweezers to fuse the solder fillet and tin from the head. After the above processing, the slave is turned on, the current rises to 470mA, and everything is normal.


Touch screen maintenance case three:


Fujitsu touch screen repair 650 suitable models: 660, 670, 253, 280, 1120, 2610, 2620, 2630. Symptom: The touch screen handwriting is invalid, the keyboard is normal, the click lever mouse is invalid, and the external USB mouse can be used normally. Process: According to the past repair experience, it can be concluded that there is no problem with the contact lens, and the point lever is damaged. Solve immediately after replacing the lever.


Touch screen maintenance case four:


The touch screen does not respond. First check whether the wiring interface is loose, then check if the serial port and the stop number are in conflict. If there is any conflict, adjust the resources to avoid the conflict. Then check whether the surface of the touch screen presents cracks. If there are cracks, it should be replaced in time. Also check the surface of the touch screen for dirt, if any, with a soft cloth. Investigate to see if the indicator light on the control box is working properly. When it is normal, the indicator light is green and shines. Contact screen maintenance case 5: No contact after use In some applications, due to the lack of grounding function, the control box shell is covered with a lot of static electricity, and then affects the operating electric field inside the control box, resulting in the gradual failure of contact. At this point, use a wire to ground the enclosure of the control box and start it from the beginning.


The above four cases describe the method of touch screen maintenance in detail. If you encounter a similar situation, you can check it yourself. If you solve the problem, you can find the maintenance personnel.