Unrooted / Locked Bootloader / AT&T HTC One (M7) will not boot/charge flashing button
Writing to you from Buenos Aires, Argentina.
I have a AT&T HTC One that is running the original firmware/software that came with it from AT&T months ago, I don't believe the firmware was ever updated; still running Android 4.1.1
Today the phone was on the table, and I heard the sound of the email notification and when I tried to turn on my phone, I couldn't.
* When connected to the charger, light doesn't come on.
* I tried the bright light trick and I can get to the bootloader. I selected the fast boot option, then later tried a factory reset. Still same symptoms.
* Sometimes it just randomly tries to boot up.
* When I Hold powre button to start up phone, the menu/back button just flash.
* Phone is warm to touch on the back.
What else can I try?