If your tablet is not responding to touch input, and you've ruled out issues like dirt on the screen or a screen protector causing the problem, you may need to perform more advanced troubleshooting. Here are steps to consider:
1. **Restart**: First, try restarting your tablet. It can often resolve temporary software glitches.
2. **Update Software**: Ensure that your tablet's operating system is up to date. Software updates can include touch-related bug fixes.
3. **Safe Mode**: Some tablets have a safe mode that allows you to boot the device with only essential apps and services. If touch works in safe mode, a third-party app might be causing the issue. Uninstall recently installed apps one by one to identify the culprit.
4. **Calibrate the Touchscreen**: Check your tablet's settings for a touch calibration option. If it's available, calibrate the touchscreen to improve accuracy.
5. **Factory Reset**: As a last resort, you can perform a factory reset to revert your tablet to its default settings. Keep in mind that this will erase all your data, so make sure to back up your important information first.
6. **Hardware Inspection**: If none of the software-related steps work, the issue might be hardware-related. Inspect the screen for any physical damage, such as cracks. Hardware problems may require professional repair.
7. **Contact Manufacturer or Support**: If the tablet is under warranty, contact the manufacturer or your tablet's customer support for guidance on repairs or replacements.
Remember that diagnosing and fixing hardware issues typically requires expertise and tools, so if you suspect the problem is related to the tablet's hardware, it's best to seek professional assistance.