Your best bet is to replace the power button with a [https://www.ebay.ca/itm/HTC-One-M9-New-Power-On-Off-Volume-Button-SIM-Card-Reader-Slot-Holder-Flex-Cable/263616864212?hash=item3d60ca1fd4:g:DhEAAOSwfpVZENc8|new unit] This is not easy to get to as HTC has a tendancy to glue everything together in there phones (eg. the motherboard is glued to the battery) But that said hears a[guide|39166|teardown guide] to help .