Diagnosis
Moisture or grease ingress under the capacitive touch panel. This creates a barrier between your finger and the sensor.
How to Fix It
1. Unplug the unit and let it cool. 2. Clean the control panel with a slightly damp microfiber cloth. Use a small amount of mild dish soap if greasy. 3. Dry thoroughly with a separate dry microfiber cloth. 4. Ensure your fingers are completely dry when operating.
If That Didn't Work
The touch panel may have a manufacturing fault or be damaged by repeated cleaning with harsh chemicals. This requires control board replacement via Philips service.
Heads Up
Never spray cleaning fluid directly onto the control panel. Always apply it to the cloth first to prevent liquid seeping into the electronics.