They sure do.I think my black screen is my moniter shutting down. Where's Atty? Do moniters go to crap? Mine is old,has been thru 2-3 computers. Light no longer works well. After it goes black it says Screen is locked or something like that when I press the top button.
Could be anywhere in the chain, though. Graphics card/chip, cables, monitor, power.
Maybe see Tom's Hardware

