I would check the following:
1) Just for curiosity, I would check to see if you have a bad VGA cable by trying a different cable.
2) If you have the ability to swap connections somehow, swap the color pins, for example green with red. This will tell you if the problem is in the monitor or what is sending it.
3) If Green is dead, I would recommend contacting Betson and see if they would exchange it for a working one.