Some Sony Xperia Z Ultra users are having a problem getting the phone to wake up51
One owner of the Sony Xperia Z Ultra says that he has to press his power button anywhere from 5 to 150 times before the screen comes back on. He also says that his display has a yellowish tinge to it. A number of YouTube videos have popped up showing the problem. So far, no word from Sony although some say that the firmware update to build version 14.1.B.0.475 solves the problem. Others say that the update doesn't help. Hopefully, we will soon see Sony spring to life with an effective update that will work for everyone.
In the meantime, you can check out some of the YouTube videos that have been posted by disappointed Sony Xperia Z Ultra owners. And if you happen to own the device and are experiencing a problem, drop us a comment in the box below.
source: XperiaBlog via XDA