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My name isXXXXX am an Authorized Servicer For Panasonic,
Have you Ever had the Unit Cleaned, If not it is Recommend, This error is coming up because the unit is sensing a slowdown in air flow.
If You can remove the back cover the filter is located near the lamp but in many cases it requires the light engine to be removed in order to reach this filter.
You could remove the lamp and run a vacuum in the light holder this would pull some of the dirt free and hopefully allow you to resume function, but the filter will need to be cleaned and you should schedule its cleaning soon,
If you wish to clean the filter yourself you will need the service Manual, as removal of the light engine is let just say... Fun, yeah let say really fun. I hated trying to remove this engine the first time, it is not as clean cut as you would think as they hide screws EVERYWHERE.
Most shops Charge Around 120-175 for a cleaning and this is probably your best bet for such an expensive television.
If you do wish to try and repair this yourself i will be happy to help you locate the service manual. Let me Know.
If you have anymore questions or need clarification, Just Ask.
Hope this Helps,