Power button broken in HP slate 7 extreme

Hi. I have been using my HP Slate 7 Extreme for over a year now. Sometimes the power button would not be responsive and I used the stylus to unlock the tab. For the past week, the power button has been completely unresponsive. Yesterday, the tab switched off due to low battery. After letting it charge for the night and affirming that it has high battery levels, I tried to switch it on. However, it is not working.

Please Help!!!