[Xperia Z2 Q&A, Help & Troubleshooting] epeace:
Hi Im new to the forum but I am finding it to be a massive resource for all things technical android. I am also new to rooting android but am technically savvy, (10 years in IT will do that). Initially it went just fine, even if a speed bump here or there. I got my Sony Z2 (starting BL unlocked w most recent Sony stock .291 firmware) rooted and flashed with TWRP and SuperSU (UPDATE-SuperSU-v2.76-20160630161323.zip) using rocker00's guide. I was then able to successfully flash ParanoidAndroid's latest (pa_sirius-6.0.3-20160809-signed.zip) and Gapps (A-GAPPS+6.0.1_14.05.2016_v5.2.zip) using TWRP recovery. I got a minor bootloop trying to get PA running, but re-flashing seemed to clear it up. It seemed to work fine although I couldn't figure out how to get the pie controls or the halo notifications to work. Without those things i couldn't see the point, so I decided to try Cyanogen (cm-12.1-20161016-NIGHTLY-sirius.zip). Apparently this uses a different recovery (CWM), I was a little worried but went for it anyway. It seemed to be fine after the first reboot. I rooted fine (same SuperSU as before) and started installing apps via Google restore. But after the next reboot, it started bootlooping. First it would cycle between the Sony screen and a blank screen, But after trying a bunch of things (I'll detail below), it just hangs at the Sony screen indefinitely.

So, what I've tried till now to fix it is:

1) First I tried to reinstall TWRP using the tool from rocker00's post with the phone in fastboot mode. The flash went without error, but did not fix the problem. I have not been able to get into recovery since the bootloop. In the process I also did a fastboot -w, which also seemed to have relatively no effect, although I would get the android robot with the blue progress once before it reboot into the bootloop.

2) With the phone in flashmode I tried flashtooling the kernel again with the same from rocker00's post (D6503_23.5.A.0.575_kernel.ftf). No effect. I also tried flashing recovery a few more times using the script from his post to no effect (i think the phone needs to be booted for this tool to work).

3) I've tried all the relevant commands from this page and this page, hoping to eradicate whatever errant code is screwing with my phone. Since fastboot seems to be the only way to interact with my phone. I tried:

fastboot flash recovery /path/to/twrp-3.0.2-0-sirius.img
fastboot -w
fastboot update /path/to/pa_sirius-6.0.3-20160809-signed.zip

the attempt to flash PA through fastboot errored with a message about not having "android-info.txt".

I also desperately tried:

fastboot erase system
fastboot erase data
fastboot erase cache

the one about data errored. the others seemed fine, but didn't change the situation.

This guide was informative yet quite useless to me, since I definitely don't want to start scripting my phone 2 days after starting this stuff. I've also scoured this forum and others for similar situations, which I've found but they all seemed to get resolved by either doing stuff I've already tried or from having a completely irrelevant problem to my own..

I'm really scratching my head here because it is all stock TWRP and Android or should be by now. adb commands aren't connecting due to stock android not having USB debugging enabled, and without being able to boot into the settings I can do nothing to change that. So all I have is fastboot. I also have a TWRP backup image I made before installing PA but till now Ive seen no way to restore it without booting into recovery.

Any help please!!!! This can't be bricked!!