Kindle not turning on

For the last few weeks, my Kindle has been acting up. Touchscreen has been behaving strangely - for example, randomly typing a letter in the same location/selected text at the bottom of the page. A few days later, it refused to start up. The solution of holding down the power button has helped, but the next day the situation repeated itself. Now, the reset does not do anything.

The kindle is charged - green light is blinking whenever the power button is pressed, but it remains in "off" state. Would be grateful for any advice.

Edit: After I knocked on the back of the Kindle, it went on and restarted. Will see if the problem continues.