Display shows U99 and the controls are locked; unit will not start.

This is usually not a fault but a safety feature.

• Disable child lock: On many Panasonic models, press and hold the Stop/Cancel or a specific key combination (refer to your user manual) for 3–5 seconds until U99 disappears.
• Power reset: If the lock will not clear, unplug the unit for 5 minutes, then reconnect and try the unlock procedure again.
• Check for stuck buttons: Ensure no button is physically jammed or held down by dirt or spills.

Warning: Do not attempt internal repair for U99; it is almost always a user setting.