1. Check whether the device is connected: Make sure that your device is connected to the computer correctly. Check the physical connection for looseness or problems. If you use a USB port, try changing a different USB port.
2. Update the driver: Open the device manager and find the category of "Ports (COM and LPT)" to see if there are any devices with yellow exclamation marks or question marks. If so, right-click the device and select Update Driver. Select Automatically Update Drivers to let the system search for and install the latest drivers.
3. Check the hidden devices: In the menu bar of the device manager, select View, and then select the option "Show hidden devices". This will show the unavailable devices hidden in Device Manager. If the port is gray or has an arrow icon, right-click and try to enable the device.
4. Clear the error in the device: In the device manager, right-click the port device that can't work normally and select "Properties". In the Properties window, select the Drivers tab, and then click the Uninstall Device button. Confirm to uninstall the device driver. Then restart the computer, and the system will automatically reinstall the driver.
5. Disable and enable the device: In the Device Manager, right-click the port device that is not working properly and select Disable Device. Then right-click the device again and select Enable Device. This will reinitialize the device and may solve the problem.
6. Update Windows system: Make sure that your Windows system has been updated to the latest version. In Windows 10, open Settings, select Update and Security, and then click the Check for Updates button to ensure that the latest Windows updates are installed.
If the above methods fail to solve the problem, it is recommended to refer to the official website or supporting documents of the equipment manufacturer for more help and guidance.