Dell inspiron P93G Blank lock screen when booting up. Shows clock date, wifi status, etc but background is blank. When trying to click, or press enter it goes to a blank screen for a minute or two before showing the partial lock screen again. Usally Iet it sit for an hour or so and come back to it I can finally get it show the proper login screen and log in. At which point everything seems to work fine. Until it locks again or gets shut down.