flashing lights on keyboard

:emotion-2:

Please list Dell model and version of windows. Example: Dell Inspiron 3543, windows 10

In the meantime, you can try the steps below:

A) Disconnect all peripherals(printer, external drive, etc...) from computer

B) Power off computer

C) Unplug the AC adapter from computer and wall socket 

D) Remove Battery from the computer

E) Press and hold in the "Power On" button for 15 seconds then release

F) Plug in the AC adapter into the wall socket, then the computer

G) Press the "Power On" button. Hopefully your computer run normally