I've had the exact same thing happen to me. It's not the button board. The monitor just won't go into VGA mode... I guess I'll have to buy a new monitor if you never figured it out
Nobody seems to have any ideas at all on this problem. I know it wasn't my buttons that kept it from switching, I've reseated the ribbon cable 100 times and it is the original buttons for the monitor. It's something wrong in the monitor, but I have no clue what.