Touch screen is not responding - Solutions - Huaqiang Electronic Network

SMD Aluminum Electrolytic Capacitor

Brand AVX TPSE226M035R0125 Low Impedance Tantalum Capacitor, AVX 22

Tantalum Capacitor

[Fault Phenomenon]: The touch screen is unresponsive and does not react to any touch input. [Fault Analysis and Resolution]: Begin by checking the wiring connections for looseness. Then verify if there are conflicts between the serial port and the interrupt number. If a conflict exists, adjust the system resources to eliminate it. Next, inspect the touch screen surface for cracks. If damage is found, replace the screen immediately. Also, check for dirt on the surface and clean it with a soft cloth. Observe the indicator light on the control box; normally, it should be green and blinking. If all previous checks are normal, proceed with the replacement method: first replace the control box, then the touch screen itself, and finally the host computer. 1) It could be an issue with the touch screen connection. One of the connections to the keyboard port (which supplies the 5V operating voltage) may be disconnected. Ensure all connections are properly secured. 2) During driver installation, the selected serial port number might not match the actual one connected to the touch screen. Uninstall and reinstall the driver to resolve this. 3) If the host is a domestically produced original machine running an OEM version of the OS, it may have been modified by the manufacturer, leading to non-standard serial communication. This can cause incompatibility with the touch screen driver. In such cases, consider formatting the hard drive and reinstalling the OS before installing the driver. 4) A low driver version may also be the cause. Install the latest driver available from the manufacturer’s website. 5) Check for hardware conflicts with serial port resources. For example, some network cards default to IRQ 3, which may conflict with COM2. Adjust the network card's IRQ to an unused one. For resistive touch screens, follow these steps: 1) Confirm that the touch screen is properly connected. If using a keyboard port for power, ensure the 5V connection is secure. 2) Check the status of the control box indicator light. If it’s off or red, the control box may be faulty and needs replacement. 3) If the problem persists, uninstall the driver, restart the computer, and reinstall it. Alternatively, try a newer driver version. 4) Check for hardware conflicts again. For instance, a network card might be using the same IRQ as COM2. Adjust accordingly. 5) If the touch screen has been in use for several years and certain areas are unresponsive, it may be damaged and need replacement. For capacitive touch screens, the following steps apply: 1) Verify the connection. If using an external control box, connect the cable directly from the touch screen through the return slot. Power should be supplied via a keyboard conversion head. Make sure the small rubber head next to the RS232 connector is removed before connecting. Connect one end to the keyboard port of the main unit and the other to the computer’s keyboard. Insert the 5V power supply into the RS232 port. Ensure the RS232 connector of the control box is correctly linked to the host’s 9-pin port. If your host uses a 25-pin port, purchase a 9-to-25 adapter. If your keyboard port is a standard one, get a keyboard-to-keypad adapter. 2) For built-in control cards, check the jumper settings on the control board. Different configurations may affect the COM port settings. Micro Touch provides jumper descriptions to help users avoid conflicts with peripherals. The COM port and interrupt jumpers should be set according to the table below: | COM Port | I/O Address | A1 | A2 | A3 | A4 | A5 | A6 | |----------|------------------|----|----|----|----|----|----| | COM1 | 3F8–3FF | ON | OFF | ON | OFF | ON | OFF | | COM2 | 2F8–2FF | OFF | ON | ON | OFF | ON | OFF | | COM3 | 3E8–3EF | ON | OFF | OFF | ON | ON | OFF | | COM4 | 2E8–2EF | OFF | ON | OFF | ON | ON | OFF | | COM5 | 2E0–3E8 | OFF | ON | OFF | ON | OFF | ON | | COM6 | 2F0–2F8 | OFF | ON | ON | OFF | OFF | ON | | COM7 | 3E0–3E8 | ON | OFF | OFF | ON | OFF | ON | | COM8 | 3F0–3F8 | ON | OFF | ON | OFF | OFF | ON | The correct configuration should be: - COM1 → IRQ4 - COM2 → IRQ3 - COM3 → IRQ4 - COM4 → IRQ3 Special cases may require different settings.