Blue line appearing on iPad screen

If it is a hardware failure, you can't repair it on your own.

I suggest that you make an appointment (*) and have your device inspected at an Apple Store or AASP (Apple Authorized Service Provider) among this list:--> https://locate.apple.com/choose-country-region . After checking it out, they'll give you all the available options.

Regards

Giulio

(*) You can do it:

• Online:--> Genius Bar Reservation and Apple Support Options - Apple;
• Contacting a local Apple Store or AASP among the list provided above;
• Using the "Apple Store" app, available and downloadable from AppStore.

Depending on the iPad and its age and if AppleCare+ was purchased, it may still be under warranty or under AppleCare+. You are going to need to get it looked at as it is a hardware issue and will need to be repaired or replaced. If it’s under AppleCare+ or warranty this could be a pretty easy option. If it’s not covered by those, then it is most likely going to be a pretty pricy repair and may almost be better replacing.

That being said, I would suggest having it looked at by Apple at a Genius Bar or have it checked out at an Apple Authorized Repair center. They will be able to tell you what it will cost and what options you have to get the issue taken care of.