Screen Backlight suddenly went off

Well I will suggest you to restarting your laptop if if didn't work then try ti rest the display driver.

Had the same thing happen on an old laptop. Try shining a flashlight at the screen, if you can barely see the picture then it’s probably just the backlight that died. I’d check the display cable first tho, sometimes it’s just loose and saves you from replacing the whole screen.

A blinking backlight that suddenly goes off usually indicates a failing LCD backlight, loose display cable, faulty inverter/LED driver, or power issue. Test with an external monitor to determine if the graphics card is working. If the external display works normally, the laptop screen or its backlight assembly likely needs repair or replacement.