I have a broken laptop screen that I can't even see on so I purchased a monitor and hooked it up to my laptop which worked pretty good for a few months. However, the display changes to the laptop sometimes when I boot up my computer. This problem has had 3 or 4 times before not counting this time. I've fixed it before by pressing the function key to switch monitors, but this time that solution wouldn't work, I have also noticed that whenever I press enter the laptop turns off. So I am left practically blind not knowing what is going on. Please help me, Thansk.