Sorry I don't have the info you need, but this is similar to what JVC
does. They use a photocell to kill the DVI board if light hits it (as
in the backboard removed). The TV continues to work, but not in HD.
What I don't understand (besides the obvious) is how these booby traps
protect the manufacturer. If anyone has the skills to hack these,
they might be able to develop the skills necesssary to bypass the
Pioneer's switch, or put black tape over the JVC's photocell.

John