My LCD briefly turns black and comes back again. Usually black for 1-2 seconds. This happens off of various actions but never while just sitting there. For example, yesterday I was moving large numbers of files to an external hard drive. As they were moving the screen would black out temporarily each time I was to be warned of a dupe file and asked if I should overwrite. I was just downloading a small program and it blacked out again temporarily when I hit the download button. Thoughts?