Wii U GamePad buttons and touch screen not responding

The most common problem is a scratch that is too deep on the touch screen, causing it to think that it is constantly being pressed. You cannot press, on the same frame (image per second), different spots on the touch screen or a button. This problem causes the scratch on the screen to press continuously, which prevents any other action. You can check if the scratch is deep enough to cause the problem by running a 4B pencil over the screen; if marks remain in the area of the scratch, the screen replacement is necessary. This method is practical because it leaves no mark other than the easily cleanable pencil (I created and used this method, it is far from being a popular or 100% proven method).

Image 1: Before the 4B method (for information, the small color changes on the touch screen show that the scratch has touched the touch-sensitive part of the screen and has therefore rendered it obsolete.)

Image 2: After the 4B method