Originally Posted by troubled_android
Did you unlock the bootloader? Flashed the right kernel? Explain a bit what did you flash and how.
I'm kinda new to this and I just did what the guide told me to do , which is the following:
For Locked Bootloaders: Root your phone using this tutorial, than install CWM using this app
Place ROM on SD-Card
Back up user apps and data. (Various apps available, search Google Play. This is a popular one)
Power off phone.
Boot to CWM (Keep pressing the Volume Down key after the Sony logo appears)
Wipe Data/Factory Reset
Mounts and Storage --> Format /System
Advanced > Wipe Battery Stats
Install zip from SD card > Choose Xperia Ultimate HD
Follow on screen instructions on AROMA.
After Complete Installation untick "reboot" and select reboot in CWM
Give the phone a good full charge, and enjoy your brand new phone!