I don't know what is going on with my kindle. I cannot turn on my kindle and now the screen keeps flashing for days with the ad appearing. I have been charging my kindle for a few days and the light is still yellow/orange. I tried holding the power button for 40s and it was still the same. While I was holding the power button, the power light flashes 4 times and then stays. I was able to connect it to my Mac but I can't do it anymore.