Macbook Screen Blank

It sounds like there is a hardware failure with the built-in Display which will need to be repaired. Have Apple or an Apple Authorized Service Provider examine the laptop to provide you with an estimate for the repair.

TuksThe1st wrote:

My macbook's display is black but it's functional on the mirrored display. Please help

Agreed, hardware issue with your built in display.

In or out of warranty you can get a free over the counter 'Apple Service Diagnostics' test /assessment

Make an appointment for a "hardware issue"—

https://www.apple.com/retail/geniusbar/

Outside the USA

https://locate.apple.com/country

From iOS device using the app to make a online Genius Bar appointment is easy:

https://itunes.apple.com/us/app/apple-support/id1130498044?mt=8

(note: due to the temporary closure of Apple Stores and the staggered reopening there may be some delays.

ref: https://www.apple.com/shop/browse/store/temporary_closures )

“Mac notebook, contact us and we'll send you a box you can use to ship it to an Apple Repair Center. We'll return your repaired product to you as quickly as possible. Depending on where you get service, you might be able to check the status of your repair online.” Start a service request https://support.apple.com/mac/repair/service

Call Customer Support (800) MY–APPLE (800–692–7753)

or

call AppleCare Support at 1-800-APLCARE (800-275-2273)

Get your Mac ready for service - Apple Support https://support.apple.com/en-us/HT209095