Our Panel PC in the workshop registers touches in the wrong place after cleaning, and sometimes triggers by itself. How do we fix it?

This symptom is almost always water or cleaning fluid left on the glass, not a failed touchscreen. First: dry it completely with a soft cloth, including the border around the edge of the glass where liquid collects, and test again. A capacitive (PCAP) screen senses capacitance, so even a thin film of water reads as a finger. If it persists: many industrial Panel PCs offer selectable touch modes in the vendor utility or in BIOS — normal, glove mode (higher sensitivity), and water-rejection mode (ignores large contact areas). For a workshop with wet cleaning, use water-rejection mode; finger response is slightly slower but there are no phantom touches. Next: update the touch controller firmware and driver for that exact model, and recalibrate if the screen is resistive. PCAP screens rarely need calibration — offset touches usually mean noise or poor grounding, so check the earth connections of both cabinet and machine. Finally, change the cleaning method: spray the cloth, never the screen.