Black vertical lines all over the screen my MacBook Air

Solution 1:

Yes, it looks like a hardware issue. You'll need to take it to an Apple Store or other Apple-authorised technician.

If it is a new Mac, then you may be able to get a free repair (or replacement). The age for which this will apply varies depending on local laws.

If it is an older Mac, you will have to pay for the repair, and you will need to decide whether the cost is worth it, or if you are better off putting it towards a new(er) Mac.

If it is a very old Mac, then you could try a "non-high-end" repair shop, though realistically, they would have to use secondhand replacement parts (e.g. the logic board) as Apple doesn't sell parts. This might be cheaper, but there's no guarantee that it will last.

You may be able to use the MBA with an external display (depending on the nature of the fault). It's worth testing before you buy a display. Obviously, you lose the portability.

Oh, and don't forget to backup your files before giving it to repair.

Solution 2:

Definitely looks like a hardware issue. I honestly don't think a system wipe will do anything. It may be worth a shot once you eliminate hardware issues though.

If it is purely a hardware issue than connecting to an external monitor should allow you to use the MacBook.