I have a sony lcd hdtv that is locked to NTSC TV system only. And I would like to find out if its possible to unlock the TV to a multi-system, supporting NTSC/PAL/SECAM, by upgrading the firmware using another region's firmware update?

Has anyone tried anything like this before?

Or is there a more simpler method, like a sequence of code/numbers from the remote to open the TV to a multi-system?