have just got new ATV. Connected to Panasonic TX-L26.TV picture keeps flashing on and off

Hey there McGill480,

It sounds like you are getting some visual issues when trying to watch your Apple TV. I would try the troubleshooting from this article named:

Apple TV (2nd and 3rd generation): Troubleshooting video issues

http://support.apple.com/kb/TS5148

Your TV picture is completely black or has other quality issues such as static or blurry video

1. Confirm the settings and configuration of your television.
   • Check to verify that your TV's video input matches the HDMI connection.
   • Refer to the manufacturer's user guide for assistance with changing your TV input or picture mode.
   • Verify that your television meets the Apple TV minimum resolution requirements.
2. Verify that the Apple TV's power cable and the HDMI cables are securely connected.
   • When connecting to power, observe the front LED on your Apple TV for activity. If no light is visible, try a different power outlet or power strip.
   • Connect the Apple TV directly to your television, bypassing any home theater receivers, splitters, repeaters, or switches temporarily.
   • Inspect all cables for any kinks, tears, or other evidence of damage.
   • Verify that the HDMI cable being used with your Apple TV is a bidirectional cable. Although rare, single-direction HDMI cables do exist. If unsure, try flipping the connection between your Apple TV and television.
   • If all else fails, try a different HDMI cable.
3. Change the Apple TV resolution:
   • Press and hold the Menu and Up button on your Apple Remote for six seconds.
   • The Apple TV will automatically cycle to the next resolution at approximately 20 second intervals.
   • Press Play on the Apple Remote to keep the current resolution or Select to manually cycle to the next resolution.
4. Reboot your Apple TV by holding down the Menu and Down button on the Apple Remote for six seconds. Allow the Apple TV a few minutes to restart.

Note: If the Apple TV video functions correctly after bypassing a receiver, switch, or repeater, please refer to the accessory manufacturer's user guide for additional support.

Thank you for using Apple Support Communities.

Take care,

Sterling