My IPad screen has gone blank with lines running up and down?

1. Reset: Hold the Sleep/Wake and Home buttons and don’t let go until the screen goes dark and the Apple logo appears (no data will be lost)
2. Lay the iPad, screen down, on your lap and give it a few good whacks on the back (on the Apple logo).
3. Make a Genius Bar appointment or contact Apple for repair.

A year ago, my ipad all of a sudden (whilst I was using it) started having coloured lines running through the image. Resetting it did no good but by the time we took it to have the screen repaired it had mysteriously sorted itself out.

Today I have had no image, just a blank screen which gradually becomes lighter. Resetting it gave me coloured lines again but still no image. However, I took the advice on line and found that whilst tapping it on the logo did nothing, dropping it gently from about 12 inches onto a carpeted floor improved it. After 3 drops it was back to normal.

Not sure why it should work and it can't possibly be good for the electronics, but it has saved me an expensive trip to the repair shop!

Looks like it may be time for #3.