This is the scenario:
My uncle has an NEC TV (not a LCD or plasma) and a few months ago, his dog ate the remote control to it. As a result, the remote was destroyed and when he clicked to the AV channels, the said "lock".
He now has a new Logitech Universal remote but the AV channels are still locked.
And this story is true!

The panasonic remote is a program director MB Universal. The NEC tv is so old that is doesnt have a menu or tv/video button on the TV itself, so I need a remote to use so I can connect and operate a DVD player from it.