Error messages that don't seem to give any information are frustrating. Error F61 is a common problem with Panasonic home theatre systems. Fortunately, it usually signals a simple problem that you can easily fix.
When you power on your system and it displays "F61," this typically means that there is a problem with the speaker cable connections. The wires may be misconnected, disconnected, cross-wired (reverse polarity) or shorted. Additionally, the error "F61" may also mean a problem with the fan or supply line. The error system is in place to prevent damage to the system from prolonged use.
Turn off the unit and reconnect the cords. Attach the speaker-cable stickers, provided with the original packaging of the home theatre system, to make the proper connections easier to identify. If this does not fix the problem, your fan or supply line may be the problem. These parts are likely defective and will have to be replaced.
If the error persists, contact Panasonic's customer support at 800-211-PANA. The error may vary by model. Visit Panasonic Online Support for a manual specific to your system and look at the troubleshooting section (see Resources).