Unexpected shutdown

tousif421 wrote:

My macbook shut off suddenly, and it isn’t showing anything on the screen. It isn’t even turning on.

So you are saying you worked through all the trouble shooting advice from the link above:

Isolate hardware or software as the cause of the issue

Hardware troubleshooting

Check peripheral devices first

Check internal RAM and third-party hardware

Software troubleshooting

If that is the case you are very limited in what you can do, from the key combination you can try , both:

Try resetting the  SMC  https://support.apple.com/en-us/HT201295

Try resetting NVRAM/PRAM http://support.apple.com/kb/ht1379

If you are dead in the water, take it in for service:

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/

or outside the USA

https://locate.apple.com/country

Check your warranty—

https://support.apple.com/my-support

From iOS app online Genius Bar appointment: 

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

.

tousif421 wrote:

My Macbook shut itself off suddenly and stopped responding completely. I have no idea what to do.

If your Mac spontaneously restarts or displays a ...or shuts down - Apple Support