Root problem PLS HELP

[TheBigMaster7]

There is this weird problem with my Xperia Z c6602. It charges only when its completely drained out!! It doesnt charges in between. So i think this is a problem of software. I googled it and many people had this problem. Now I want to Root and Flash a custom rom.
But i am able to only root it using KINGROOT. Now i need to UNLOCK THE BOOTLOADER TO SET UP CUSTOM RECOVERY But i dont know how to do it because that usb port is not working!! What it does that only charge when completely drained and the phone doesnt even GETS RECOGNISED By PC!
I am stuck TOTALLY STUCK!!
I NEED A WAY TO JUST DOWNGRADE OR FLASH ANY ROM. I AM A TOTAL NOOB IN THIS CASE. I THANK YOU FOR YOUR TIME.
PLS HELP ME PLS

 

[unmaskedluke]

Use fastboot method

 

[TheBigMaster7]

use fastboot method

pls tell me how?!!
And doesnt fast boot requires a pc??!

 

[Zerikwan]

I never know the way to put TWRP without PC before but there is a new Official TWRP App on PlayStore. It means you can flash TWRP without PC (I never test it myself). Maybe you can give it a shot.

I don't know If Kingroot would work but to increase success rate, install and run supersume.apk IMMEDIATELY after phone rooted. Means No reboot after rooting process is done. Supersume will install SuperSu for root management. Note that Supersume is a paid app.

The steps are:
- make sure your bootloader is unlocked (unlocking process by PC). There is a thread about this somewhere on this forum, but I prefer the Official way. Much reliable.
- install Kingroot and begin the rooting process (btw, I'm using kingroot v4.5 back then).
- If succeed, DON'T REBOOT, install supersume and begin the process (note: it's a paid app so if you wanna continue without supersume, you are free to go to the next step).
- Install Official TWRP App on playstore. Then install The latest TWRP for Yuga.

Note: I don't guarantee that this method will work 100%, and if you can't unlock your bootloader then there is nothing you can do. Sorry.