Back to maker or seller for what to do next.
Here I only have a reset that some forget about. I remove battery, SIM and memory cards then press and hold the power button for over a minute. Release, slip in the battery, plug in the charger and try again. If it doesn't come back I'm talking to maker or seller.
Hello i have an HTC ONE M7 that just blacked out when charging and when i tried to do a hard factory reset it failed to reset says its locked anybody to help? thanks