The display shows 'BUTTON STUCK' or the menu scrolls uncontrollably; the front panel button appears to be always pressed.

Safety first: Disconnect power before working on the front panel.

• Step 1 – Physical check: Press the button repeatedly to see if it returns fully and feels normal. If it feels sticky, contamination may be present.
• Step 2 – Clean button area: Remove the front cover and gently clean around the button with isopropyl alcohol. Allow it to dry completely.
• Step 3 – Inspect switch: Examine the tactile switch on the LCD or control board for cracks or bent leads. If damaged, replace the switch or the entire LCD/control board.
• Step 4 – Test without button: Temporarily disconnect the button leads (if possible). If the error clears, the button or its wiring is the cause.