Htc One M9 Brick
All these tasks aren’t official and the warranty of your phone will get void when applying the same, which means that if something bad happens you can’t take your device back to service for technical assistance, but you are the one who has to unbrick the handset.Before starting these procedures, keep in mind that you might need a computer if you will try to downgrade or reinstall the stock Android OS, so prepare it from the start by deactivating the antimalware tools installed there as they might stop you from applying any of these procedures. You must also find the original USB cable for establishing the connection between your One M9 device and the PC and enable Developer Options by going into Settings About phone and tapping on Build number seven times;You must also enable USB Debugging mode, so enter into Settings Developer options and tick the USB Debugging checkbox placed under Debugging section, make a backup of your precious data and to plug in the charger especially if there is less than 60% power left. How to Unbrick your HTC One M9 Device:Perform a hard resetI want to tell you from the start that most of the problems that you are experiencing such as bugs, lags, boot loops, the impossibility of taking calls or sending messages, force closes errors, battery drain problems and more can be resolved with a simple hard reset.Here you can find a tutorial on, but if you haven’t been successful and the issues are still there, I have another solution:Enter recovery modeIf the first suggestion did not help fixing your bricked device, then entering recovery mode might be the key to your problem.