my Xperia Z2 suddenly stopped working completely!

[Treb1994]

I woke up this morning to find my Xperia Z2 frozen with a black screen, I forcibly restarted it, but afterwards, the real issue emerged. No matter what I did, the device freezes almost instantly after I restart it using the Volume Down button + Power button every single time!!!

I've been searching online for a solution to the problem, I tried to flash the device using flashtool, tried using Sony companion, tried using the ADB command prompts... all failures. Even when I keep the device shutdown, after the flashtool requests that I plug it into my PC and that I keep holding the Volume-down button, the green light appears and the device freezes again, and after about 20 seconds, my PC gives me a "the connected USB device malfunctioned, and it's unrecognized by Windows" message. The same happens when I try using Sony companion.

Up till now, I haven't found any clue that could help me, I've tried the mentioned software, made several hard-reset attempts, tried every button combination and method I could find online, but still with no use.

This device is very precious to me, so I would appreciate it a lot if someone could provide me with a solution.

Thanks in advance guys... 

[Uliwooly]

@Treb1994 

A while ago I had a similar situation with an Xperia Z, what worked for me was to use a different computer, I've seen other users that by using a different USB cable and port did the trick while using Xperia Companion. 

Could you elaborate on what happened before this issue? did you dropped the phone? flashed it? etc 

[Treb1994]

Thank you for responding...

Actually, nothing happened at all... I was watching YouTube just before going to sleep and sat the alarm, at morning, I woke up by myself, and when I turned to the phone to check the hour, I found it frozen with a black screen...

Although, now that you have mentioned it, I had been downloading stuff online and I left them to continue downloading before going to sleep, despite running low on empty space in the internal storage of the device.

Could it be that the internal space was 100% filled, consequently causing the device to freeze for having no more free room to cache data on launch... but even though, I though that performing a hard reset for the device solves this problem.

[Uliwooly]

@Treb1994 

What if you restart the phone > then press and hold the volume down key > this should boot the phone in safe mode, see if you experience the same lag

[Treb1994]

I tried rebooting the phone using the combination you mentioned before several times, tried various combinations from different websites, and tried -as you suggested- using different USB cords and ports. I switched to another laptop and used all its USB ports using 3 different USB cords for the Sony companion app. Nothing has worked so far, and I'm starting to lose faith... 

the same thing always occurs, the phone freezes instantly after launching, and the only thing that is doable at this point is to press the power button along with the volume-up button until the 3 vibrations happen.

[Strampke]

You're good at ADB.

So why not try to uninstall all 3rd party packages. 

Maybe one of those is the culprit.

Here are some commands (just in case)

filter to only show disabled packages
adb shell pm list packages -d
filter to only show enabled packages
adb shell pm list packages -e
filter to only show system packages
adb shell pm list packages -s
filter to only show third party packages
adb shell pm list packages -3

and when buttons fail:

If you just need adb you can stop here, if you want to go on to fastboot, continue.
- Type: adb reboot-bootloader
- Type: fastboot devices
And you're there.
No more hassling around with Vol-Down and plugging in.
- Type: fastboot reboot to end the session nicely

Better access with Linux than Windows?