HTC One M7 Turned off. I tried doing Power +Volume down, factory reset.Phone just vibrates and goes to black screen again.

[kosarajusandeep]

HTC One M7 Turned off. I tried doing Power +Volume down, factory reset.Phone just vibrates and goes to black screen again. Please help.

I am getting a locked message on the boot loader screen.

 

[Saga Lout]

I think that failed because it's supposed to be Power and Volume Up.