Likely causes, most useful checks first
- Debris, moisture or an object interfering with the touch surface/frame.
- External-source calibration or scaling mismatch.
- USB extension instability.
- Touch hardware fault.
Safe checks
Clean and clear the touch area
Turn the display off and use the manufacturer-approved dry cleaning method. Remove objects resting against the bezel.
What the result means: Retest after the surface is dry and unobstructed.
Compare local and external touch
Test the same screen areas in the panel interface and on the connected computer.
What the result means: A problem only on the computer input suggests scaling, calibration or USB path.
Test direct USB
Bypass USB extenders, hubs and wall plates.
What the result means: Stable direct touch identifies the external USB path.
Use approved calibration
If the exact guide provides calibration, run it with the display at its normal resolution and scaling.
What the result means: Do not use service-menu calibration without authorised documentation.
Sources
- Clevertouch Plus user documentation — Clevertouch
Reviewed under the BoardFaults safe-external-check policy · risk class: low · updated 2026-09-03