My name is Varun and I work for the Social Media and Community Team at Dell.The problem you are facing with the system is that unfortunately It appears to be an issue with the lcd of the system has gone corrupt. But will request you to follow the below troubleshooting steps.
1: Check if the Dell Screen comes up on startup, if yes try safe mode by pressing f12 at the time you turn on the system and check weather u get any display there or not
2:If the system is able to boot to safe mode, uninstall the drivers and restart in normal mode, then reinstall the driver from www.support.dell.com
3:Try external monitor.
4:Run LCD BIST (D + Power Button) (If No Go then).
5: Run PSA using Fn + Power Button and wait 2-3 min for any beeps. If you hear the beep noise then it means the lcd needs to be replaced.
If you have any question regarding the troubleshooting steps please reply us back .