Under the glass is the digitizer, which its job is to sense the capacitance in your fingers along with slightest of pressures to send the signal of your placement of fingers through the devices internal components ,where they are arranged in a specific way and pushed to the LCDscreen in a readable format . Now here is why in so less of terminology iv explained this as elementary as possible. Your home button does not have a solid connection to power up as in a wired ckt.,it floats on a contact skid and is
A momentary switch. So when depressed it only has to make and break.
It is most likely ,that the contact skid has slipped off of its floating supports that is in the press to MAKE (energize or power on ) the device
And at the same time it is held in the maintained or normal position
(The home button up or BREAK ) position as it is supposed to do .
If it was the break floating skid that was knocked out of position you would not be able to turn Off OR DE ENERGIZE. however the case is the bottom line is the glass and the digitizer will need to be removed to
Repair .......sorry freind..... Good luck best to ya. This reply is written to help others understand a little more about some issues that perhaps is of useful interests . And the dates are irrelevant.