Solved! Turned of laptop during windows system restore.

[Purujit]

I was having blank screen on my laptop so I
connected it to a external monitor and it was working there. Then I did a windows system restore but I accidently shut my laptop down in between of the process , not I am getting a blank screen on my external monitor.

 

[AlHuneke]

If you have data you need to keep on the drive it will be more difficult. If you want to start from scratch, create an install USB. Do this by following the steps at https://www.microsoft.com/en-us/software-download/windows10). Select the option to make media for another computer. Boot from the USB. A clean install will erase everything. I don't know if a reinstall option will be available in your condition.

 

[Purujit]

If you have data you need to keep on the drive it will be more difficult. If you want to start from scratch, create an install USB. Do this by following the steps at https://www.microsoft.com/en-us/software-download/windows10). Select the option to make media for another computer. Boot from the USB. A clean install will erase everything. I don't know if a reinstall option will be available in your condition.

So basically problem is with the operating system right?
I went to a repair shop he told me motherboard might be faulty , which cannot be the case because it worked on external monitor right?

 

[AlHuneke]

Of course it could be a bad motherboard, but you said it was working until you interrupted it. Try to boot the USB install. That will give you the answer.