Analysis and treatment of common faults of touch screen

I believe that many people have encountered the situation that the touch screen cannot be used due to malfunction. This is mainly because the touch screen is a relatively sophisticated device, and the touch screen is mostly open to the public. Its frequency of use is high and the quality of users varies, which causes frequent malfunctions. The following introduces some solutions and maintenance methods for some common malfunctions of the touch screen:

When the touch screen fails, you should first check whether the control card power supply is normal, whether the Windows driver is installed normally, and then check whether the touch screen calibration under Windows is completed, whether the parameters in "Touchscreen Control" are correct, and whether the serial port is normal and the serial port line is connected properly.

The following are some examples to illustrate the diagnosis and treatment methods of touch screen failures.

1. The touch screen is inaccurate

[Failure phenomenon]

For a surface acoustic wave touch screen, touching the display screen with a finger cannot normally complete the corresponding operation.

[Fault analysis and processing]

This phenomenon may be that the reflective stripes around the sonic touch screen are covered with dust after using it for a period of time. You can wipe them with a dry soft cloth, then turn off the power, restart the computer and recalibrate. It is also possible that the reflective stripes of the sonic screen are slightly damaged. If this happens, it will not be completely repaired.

If it is a capacitive touch screen, you can run the screen calibration program in the following cases: (Start-Program-Microtouch Touchware)

1) Complete the driver software installation for the first time.

2) Every time after changing the monitor's resolution or display mode.

3) Each time the display area is changed.

4) Each time the frequency of the controller is adjusted.

5) Every time the cursor does not correspond to the touch point.

After calibration, the calibrated data is stored in the controller's register, so there is no need to calibrate the screen every time the system is started.

2. The touch screen is unresponsive

[Failure phenomenon]

One touch screen does not work, no response when touched anywhere.

[Fault analysis and processing]

First, check whether the wiring interfaces are loose, and then check whether there are conflicts between the serial port and the interrupt number. If there are conflicts, adjust the resources to avoid conflicts. Then check whether there are cracks on the touch screen surface. If there are cracks, replace it in time. Also check whether there is dust on the touch screen surface. If there is, clean it with a soft cloth. Observe and check whether the indicator light on the control box is working properly. When normal, the indicator light is green and flashing.

If the above parts are normal, you can check the touch screen by replacement method: first replace the control box, then replace the touch screen, and finally replace the host.

If it is a surface acoustic wave touch screen, the following maintenance can be performed:

If it is a resistive touch screen, the following maintenance can be performed:

1) Check whether the touch screen is connected correctly. Check whether one of the wires connected to the keyboard port of the host (the 5V touch screen working voltage is taken from the keyboard port) is connected. Please check the connection.

2) Observe the light on the touch screen control box. If it is off or red, it means the control box is broken and please replace it.

3) If it is confirmed that the above situation is not the case, please delete the touch screen driver and restart the computer to reinstall the driver, or replace it with a newer and higher version of the driver.

4) Is there any device in the host that conflicts with the serial port resources? Check each hardware device and adjust it. For example, the default IRQ of some network cards after installation is 3, which conflicts with the IRQ of COM2. In this case, the IRQ of the network card should be changed to an idle IRQ. It may be that the computer motherboard and the touch screen control box are incompatible. Please replace the host or motherboard.

5) If the touch screen cannot be touched in some areas after using it for a long time (3-4 years), the touch screen may be broken. Please replace the touch screen.

If it is a capacitive touch screen, the following maintenance can be performed:

3. The touch screen response time is very long

[Failure phenomenon]

A touch screen takes a long time to respond after touching the display screen with a finger.

[Fault analysis and processing]

This may be due to moving water droplets on the touch screen, just wipe it with a dry soft cloth. It may also be that the host is too low-grade, such as the clock frequency is too low. If this is the case, it is best to replace the host.

4. Part of the touch screen is unresponsive

[Failure phenomenon]

A touch screen, after touching the display screen with a finger, some parts of it become unresponsive.

[Fault analysis and processing]

This may be because the reflective stripes on the touch screen are partially covered, which can be wiped clean with a dry soft cloth. It is also possible that the reflective stripes on the touch screen are partially scratched by a hard object and cannot be repaired.

5. The touch screen works normally but the computer cannot be operated

[Failure phenomenon]

A touch screen was tested and found to be normal by itself, but after being connected to a host computer, the computer could not be operated.

[Fault analysis and processing]

This may be because the touch screen control card receives the operation signal before the host starts to load the touch screen driver. You only need to cut off the power and restart the computer. It may also be that the touch screen driver version is too low and the latest driver needs to be installed.

6. The touch screen does not respond when it is turned on for the first time after installing the driver

[Failure phenomenon]

A touch screen becomes unresponsive when it is turned on for the first time after the driver is installed.

[Fault analysis and processing]

First, confirm whether the touch screen line connection is correct. If not, shut down the computer and connect all the lines correctly. Then check whether there is any device in the host that conflicts with the serial port resources. Check each hardware device and adjust them. For example, the default IRQ of some network cards after installation is 3, which conflicts with the IRQ of COM2. In this case, the IRQ of the network card should be changed to an idle IRQ.

7. Touch becomes unresponsive after a period of use

[Failure phenomenon]

A touch screen becomes unresponsive after being turned on and used normally for a period of time.

[Fault analysis and processing]

1) Check whether the hard disk is turned off in the "Display Energy Saving Settings" of Windows 9x. The method is to right-click on the desktop, select the "Properties" command, then select the "Screen Saver" tab in the dialog box, click the "Settings" button, and set the parameters to "Never" except for "Always on" in "Power Scheme".

2) In some applications, due to poor grounding performance, the control box shell will be filled with a lot of static electricity, which will affect the working electric field inside the control box and cause the touch to gradually fail. In this case, use a wire to ground the control box shell and restart it.

3) Since the surface of the surface acoustic wave touch screen is full of acoustic waves when it is working, if the touch screen is not wiped for a long time, excessive dust will accumulate, blocking the reflection stripes of the waves, causing the touch screen to not work properly. For touch monitors, you can use clean business cards or banknotes to gently wipe off the dust on the surrounding reflection stripes through the gap between the monitor front cover and the touch screen, and then restart the computer. For touch all-in-one computers, you can open the front cover of the monitor, wipe off the dust on the surrounding reflection stripes with a clean towel, and then restart the computer.

4) Many touch screen control boxes of all-in-one machines draw power from the power supply of the all-in-one machine instead of from the host machine, so you should also check whether the 5V output of the all-in-one machine power supply is correct. Sometimes the instantaneous current is too large, causing the fuse to burn, and the fuse needs to be replaced.

8. Touch screen click accuracy decreases

[Failure phenomenon]

A touch screen has reduced click accuracy and the cursor is difficult to position.

[Fault analysis and processing]

1) Run the touch screen calibration program. (Start--Settings--Control Panel--Sonic Screen---Calibrate button).

2) If it is a newly purchased touch screen, please try to delete the driver, then turn off the power of the host for 5 seconds and then restart it to reinstall the driver.

3) If the above method does not work, the reflective stripes of the acoustic screen may be slightly damaged during transportation and cannot be completely repaired. You can deviate from the calibration center in the opposite direction (relative to the direction of the mouse deviation) by an equal distance to locate it.

4) If the acoustic screen is inaccurate after using it for a period of time, it may be that the reflective stripes around the screen or the transducer are covered with dust. If you are using our company's KA-type cabinet, you can open the top cover and use a dry soft cloth dipped in industrial alcohol or glass cleaning fluid to clean its surface, and then re-run the system. Note that the upper left, upper right, and lower right transducers cannot be damaged. Then power off and restart the computer and recalibrate.

5) There are water droplets or other soft objects stuck on the surface of the touch screen, and the touch screen mistakenly judges that there is a hand touch, causing the surface acoustic wave screen to be inaccurate. Just remove them.