Check if the laptop finishes Power on Self test
Restart the laptop and check if the keyboard status lights flash or show any specific pattern.
Also, press the Caps lock key while the laptop is powered on and check if the light is illuminated
You can try to perform the Dell Diagnostics to determine if it is a display issue:
1. Turn off the computer; press and hold the <Fn> key, push the power button and release the keys simultaneously.
2. A blue screen will appear stating Pre-boot System Assessment.
3. If there is no display, you will hear a beep corresponding to this message, 'Were color bars displayed?(y/n)'.
4. Press 'N' key if the color bars are not displayed. During the LCD BIST, a solid color screen is shown and five different colors are displayed. While the colors are displayed, the system beeps every 2 seconds and the lock lights (Num Lock, Caps Lock, and Scroll Lock) illuminate to indicate the test is running.
5. If there is no display during the LCD BIST, you may have to reseat the display cable.
6. Please connect the laptop to an external monitor (if available) and toggle the display using <Fn> and <F8> key.
Hope this helps.
Thanks and Regards,