Just in case anyone's wondering why overscan is so "popular", the overall picture size, the 'raster', is affected by, among other things, the high voltage value.

As TVs age, the voltage drops a little, so manufacturers deliberately set the overscan to pre-compensate, so you won't have black edges as the TV ages.

If anyone here owns an older, fixed-resolution computer monitor, you probably have a similar black border that can't be adjusted away.

Larry
www.fineelectricco.com