My XPS 15 will randomly crash to a black screen with the backlight and keyboard still lit. Caps lock key doesn't work when this happens either which indicates to me that the entire system has crashed and not just the screen. This usually happens when the laptop is moved. Sometimes instead of a completely black screen, I get small blue bars covering the screen. After a crash like this, the laptop often won't boot back up after I force a shutdown. Usually, the battery light blinks 3 times white and then 3 times orange for about 30 seconds. I have to let the laptop sit for a few minutes before I can boot it back up.
I've installed all of the latest drivers and bios from Dell's website, but nothing has helped.