and the screen work fine tells me that you have a driver issue . Uninstall the graphics driver and get the proper driver from Dell
So I've been troubleshooting this problem for a month or so. My laptop screen does not show anything apart from a faint gray back light.
I should mention I can connect to an external monitor with an HDMI cable just fine and can operate the laptop this way.
What I have tried so far:
1) power drain by holding power button and removing battery etc . . the most common troubleshooting video and guide to be found online.
2)Motherboard swap. No change.
3)HDD replacement. Original HDD did show errors with SeaTools scan software, so I replaced it with an SSD which had Windows 10 preinstalled. I purchased a product key and the SSD works fine, but no change to the screen.
4) Battery replacement. Original was dead. New Battery works fine and takes a charge.
3)Driver updates, Bios updates, hardware scans, and everything else available through SupportAssist. All tests come back with no issues found.
4)Booting to Linux via USB stick. The screen works just fine when I do this, oddly enough. I will put a picture below. Maybe this is the way to go. I could install Ubuntu if the screen will work this way.
5)LCD test patterns. I can do this and the test patterns will show on the laptop screen. Nothing when I boot to Windows, though.
Off the top of my head, I believe that is all I have done. I tested the motherboard and various components with a multimeter and made sure all connections were solid. I'm not sure what to do next. Any help or advice would be appreciated!