Precision 5470 Random No Display Issue

Hi all, 

We have a user that has had the same issue on their Precision laptop twice, where the laptop keys and power button light up when you press the power button, but the screen doesn't turn on. Eventually the laptop appears to lose power and the system lights go out, all while being connected to a power adapter. When I had it on my bench, I tried multiple reboots, hard shutdowns etc and all resulted in the same black screen with illuminated keys. I also tried the built in screen test on boot up but got no response from the display.

There was never a diagnostic LED code in either case, it looked like the laptop would boot normally aside from the black screen. I also tried connecting it to an external monitor during boot but that did not output anything. I am guessing that the laptop is booting until it gets to the BitLocker screen, and due to no user input, the laptop eventually shuts itself down which if I'm not mistaken, is normal behavior (please correct me if I'm wrong, I'm still a newb). 

In each case, I have had to perform a flea power drain hard reset, and each time the laptop was revived and passed basic and advanced diagnostics. I am just hoping to pick your brains as to what the customer might be doing to cause this (if anything), and if anyone else has experienced this on a personal device or in an IT support environment and what you might have done to resolve it.