K5 power button doesn't work on Kindle Touch

I bought my Kindle Touch on April 2012, and it seems now that power button doesn't work any more on my Kindle Touch, no matter pressing it or holding it for a long time.

I run the command:
and when I press power button, it is not detected, while pressing HOME button does.

Does this mean there is something wrong on the hardware level, so I have to repair it?

At the time, the main problem is that I can't resume from screensaver state by pressing power button, but have to plug it to a computer. It is so inconvenient.

I've tried running "~ds" in the search bar to disable the screensaver, but doing so would prevent Kindle from entering into suspend mode, which leads to consuming more power.

I get to know from here that command
would simulate power button pressed event, so is it possible to set pressing HOME button to execute this command when in screensaver/suspend mode?

Thanks!