I have a Grundig tp 623 tv and tonight it has developed a problem.
During watching a programme it suddenly flipped into childlock mode (even
though the remote control is broken and isn't even in the same room!).

Nospam-

Your story reminds me of the way some computers act when their CMOS battery
dies. In your case, it may be that the childlock mode is the default.

If this happens to be the root of your problem, you will still need that remote
to reset it after you replace the battery.

Fred