iPad has grey lines
Recently, I dropped my iPad upon (hard institutional) carpet, as which point, grey lines started rolling across the screen, (examples at the end) but after a little while I came across someone who had fixed the issue by whacking it with some vigor against their knee. I tried this, and it fixed my issue. Yesterday, my iPad was whacked by my friend, and now I have reencountered my issue. I tried whacking it, as it was what worked before, but this time it didn't work at all. I have whacked it as hard as I can without being dangerously close to breaking it, and I'm all out of ideas. I would rather not have to go have this fixed by the big Apple machine, but I could pay for it if it were to come to that.
Thanks!
iPad, iOS 7