I have an unrooted Z2. With around 30% battery left, I put it in the charging dock on my desktop yesterday evening. After 1 or 2 hours, I noticed that the phone is completely dead - no LEDs are blinking, no vibration, nothing. I tried pressing the power button alone, in combination with VolumeDown, VolumeUp, CameraButton, for more than 30 seconds each. I tried pressing down the tiny red button next to the SIM slot for awhile. Nothing. Phone is dead like a brick.
The only result I'm getting is when I plug it into my computer (ubuntu 14.10) - the LED bar on top is showing a constant red color in this case. Doing the button presses outlined above in this situation is also pointless.
I'm installing flashtool for Linux right now, the connection is pretty slow and it will take awhile. I hope to find out more afterwards. I'm a newbie when it comes to flashing sony phones, only found out now about flashtool. Any advice/tip on how to proceed, or if it even makes sense to dig into this, is highly appreciated.
Thanks in advance!