i built a computer about a year ago and have never had a boot screen it just stays black then boots up to the windows screen.
Most likely BIOS or UEFI is at a resolution the Panasonic TV doesn't support, such as 1280x1024. Windows loads the correct drivers and support for your TV's 720 or 1080, but the BIOS or UEFI doesn't output those resolutions. Only fix I know of is to use another monitor that will work with 1280x1024, unless your mobo people make a patch to change res to support older TV's. I have this issue too.