Alright. My brother bought a used Xperia Z about 2 weeks ago. After using it some days, suddenly this happened. The red LED always stays on while the screen is on. And this is a rare problem. I don't see any problems like this before in XDA. The phone is not rooted nor the bootloader has been unlocked. Can someone help fix this problem, or tell me what partition is damaged, etc? I can't confirm this is a HW damage coz it's not dropped, or punched, etc The red LED acts normally if the screen is off (e.g. while charging, notification, etc).
bro you can try flashing stock rom again.
---------- Post added at 12:51 PM ---------- Previous post was at 12:45 PM ----------
download 4.4.2 official ftf from here https://mega.co.nz/#!Bk0XlY7S!7rhLzB...omXmNTcrI3h4Vc
download flashtool from here http://www.flashtool.net/download.php
after installing flashtool go to c: then flashtool folder
go to drivers install from exe file, select flashboot and fastboot and finish installation
open flashtool, click on the lightning button, select flashboot.
select the firmware downloaded(make sure you cut paste the ftf file in the firmware folder of flashtool folder)
put phone in flashmode when prompted(hold power down key and connect usb)
once flashing is complete disconnect and switch on the phone