Black screen and alarm issues following Marshmallow update

[dreamee]

Hi all,

I have a D5803 and since updating to Marshmallow I've been having a couple of issues. I was wondering if anyone else out there has been having the same problem/s.

1. A few moments after restarting the phone I experience a black screen. The only way to get the phone back is to hold down the power button until the Power off/Restart/Back/Home screen icons appear and then return to the home screen. This seems to happen only once, after turning on or restarting the phone.

2. The bigger issue. When the alarm goes off, it only shows the wallpaper, it doesn't show the alarm, or the snooze button, or the swipe to turn off icon. The only way to turn the alarm off is to hold down the power button until Power off/Restart shows and then restart the phone. Interestingly, this glitch doesn't occur when I take the phone out of its case; out of the case, the alarm seems to work fine, but when returned to the case, the issue returns. If I set the side keys to dismiss, it will dismiss the alarm and the phone returns to normal - but I don't always want to dismiss the alarm, some mornings I want to snooze, so this doesn't really solve the problem for me.

I attempted a software repair with Bridge/Companion, but the softwares seem to have issues with my set-up, I'm unable to either update or repair using either Bridge or Companion.

I'd love to hear if anyone else has had these problems, particularly the one with the alarm, Sony online chat support just said that there have been no issues reported regarding the update to Marshmallow.

[Sas4]

Hi . I have exactly same problem. If I put my phone in case the wrong way round it works fine. I'm baffled to say the least.

[dreamee]

Does your case have brackets along the full length of the long sides? It seems like these cases interfere with some sensor.

[VitorF]

Hi, I had exactly the same issue, searched everywhere for an answer, no one really knows how to fix it.

Ignore sony customer service, they have no idea, ignore people who say its hardware, I knew it wasnt hardware because when I installed kitkat and lollipop, it doesnt happen, only on marshmallow.

I also knew if couldnt be a third party app, because there wasnt any installed.

This issue is some problem with style cover, thats the screen that comes up, strange I deactivated the style cover but after boot, it kept activating itself. The alarm issue was fixeable by installing a third party alarm clock, but the issue would still come up after a reboot, so I had to find a fix just in case I'd sell the phone to someone.

To note I have never used a cover of any kind, neither screen protector or anything at all.

I managed to fix it, with Flashtool, a firmware I had downloaded from the internet, Global 23.5.A.1.291 R3D,  check the EXCLUDE TA, and also I checked the SKIP FINAL CHECK.

To note, my bootloader is unlocked, which I believe comes like that from the shop.

Strange that I think I had tried this before, just a little note, when Flashtool asks to switch off the phone, I waited around 15-20 seconds before connecting to computer (Power and down button). 

Also, I never put a case on this phone so it was happening without a case.

Never had the issue again