I have struggled with this heating - charging - battery drain issue since the KK update, it has been an unmitigated disaster from day one
I have taken several steps to cure the issue and although I thought I had on several occasions it does rear it's head again, ultimately I believe it has something to do with the wtite restrictions on the ext SD card which I very strongly resist and disagree with - if want to buy a memory card and install it in my phone it has got nothing to do with google ast what I choose to put on it and how they have made a huge policy error right there
Here are my findings after going through the motions for several weeks to get a working and stable phone
First - under 4.3 firemware I had no issues and my phone was very stable
I also have a Smartwatch connected - which complicates the issue, and a 64gb sandisk ext SD
After updating to KK I had the following major issues
- The phone was constantly warm (draining the battery) on standby
- When using the phone it got very hot - the screen brightness dimmed (saving power) and very sluggish
- When on the charger sometimes I had to turn the phone off to charge it as there was not enough ebergy from the charger to compensate for the huge battery drain - a warning was also displayed on the screen
- If I did manage to get it charging without turning off it was very slow to charge
- manually unmounting the ext SD sometimes fixed the issue
- I did a complete facoty reset and update repair (no apps installed) - no change
- removed all content from my ext SD card and wiped it with the phone (reformat)
- scanned all the content that was on the sd card on my PC looking for errors - none found
- copied all content back to sd card - still had problem
I noticed that in settings/power management/battery the mediaserver was always active 40% and dowload
throughout this period I did have times when my phone was stable and operating normally but maybe only for a few days
Still no apps installed
I went into settings/apps/all and disabled as many as I could - still problems
Then I discovered a setting in setting/accounts/google/Ads and ticked the "opt out of personal based ads" and I thought I had fixed the issue, my phone was normal for weeks...............but
I copied a new album onto my music folder on ext SD and all the issues came back described above - 12 tracks of music in MP3 format - to fix this I moved the album to my internal sd and left it there for a few days then moved it back - no more problems
I believe the issues described above are caused by no one single thing, I think it is a collection of problems that appear showing similar symptoms which make this a very complicated issue, ultimately I believe the fault is with google and their very poorly written code - if you do a search on the net you will find that these problems also exist on their own devices - so it is not exclusively Sony
Further - just recently after an update to Skype and Chrome my phone has now started doing a reboot cycle - it seems this happens after I use skype but at this moment not verified
I also had a new problem were the daily alarm I had set could not be turned off when it activated and the screen remained blank, the only way I could stop the alarm was to hit the reset button and reboot the phone
I believe these last two recent issues are conneted
All in All KK upgrade has been a horendous experience for me and I'm sorry I didn't stay with 4.3, it is a daily effort to keep this phone functioning and useable - but I must also conclude that IMO the blame for this KK debacle lays firmly with google - the reason for my conclusion is a simple one - these issues are not exclusive to Sony
