Xperia Z Ultra Stuck on Sony screen

antrax360

Senior Member
Jun 16, 2011
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my xperia device is stuck on the sony logo. wont pass that part. doesn't go into flashmode or fastboot, nothing. what can I do plz I need help. cant use flashmode on the pc as the computer never recognizes the phone bcuz it doesn't go into fastboot mode.
 

Klaos3000

Senior Member
Sep 17, 2015
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If your phone even starts, then fastboot and flashmode should work just fine. What's the last thing you did before it wouldn't boot?

1. Hold VOL UP while plugging it in the USB on your computer. The LED should get blue

2. Either use fastboot through command-line or use QuickIMG to boot a custom kernel with recovery.

3. Flash or restore a ROM
 

antrax360

Senior Member
Jun 16, 2011
181
9
0
If your phone even starts, then fastboot and flashmode should work just fine. What's the last thing you did before it wouldn't boot?

1. Hold VOL UP while plugging it in the USB on your computer. The LED should get blue

2. Either use fastboot through command-line or use QuickIMG to boot a custom kernel with recovery.

3. Flash or restore a ROM
I was trying to unroot the phone to go back to stock and update to stock lollipop. the led lights don't light up anymore, holding volume up or down doesn't do anything as soon as I plug in the usb cable the screen comes on and it stays on the sony logo.
 

najoor

Senior Member
Mar 11, 2014
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Los Angeles
my xperia device is stuck on the sony logo. wont pass that part. doesn't go into flashmode or fastboot, nothing. what can I do plz I need help. cant use flashmode on the pc as the computer never recognizes the phone bcuz it doesn't go into fastboot mode.
Do the following exactly as outlined.
1- with the phone DISCONNECTED from your pc or charger, hold the power and up buttons until it vibrates and turns off.
2- open the flashtool and select an ftf to flash, and wait for the message that asks you to connect the phone in flash mode.
3- the phone must still be off. Hold the down button and connect the phone to the usb port in the pc. The flashing will start.
 

antrax360

Senior Member
Jun 16, 2011
181
9
0
Do the following exactly as outlined.
1- with the phone DISCONNECTED from your pc or charger, hold the power and up buttons until it vibrates and turns off.
2- open the flashtool and select an ftf to flash, and wait for the message that asks you to connect the phone in flash mode.
3- the phone must still be off. Hold the down button and connect the phone to the usb port in the pc. The flashing will start.
I tried that. Doesnt work
 

Klaos3000

Senior Member
Sep 17, 2015
295
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I was trying to unroot the phone to go back to stock and update to stock lollipop. the led lights don't light up anymore, holding volume up or down doesn't do anything as soon as I plug in the usb cable the screen comes on and it stays on the sony logo.
How did you try to unroot? It's weird if you don't have working fastboot or flashmode, and without those, you're pretty much screwed. Those two should work even if you screw up big-time, like flashing a wrong kernel, but you must have done something weird if they stopped working?

And let me get this straight, you are pressing and HOLDING the volume buttons when you plug it to your computer, right? Make sure that the device is completely off by pressing and holding POWER + VOL UP. It'll vibrate a couple of times. Note that you're not supposed to be connected to the computer, since it'll then just boot again.

Then press and HOLD VOL UP for fastboot (blue LED), OR VOL DOWN for flashmode (green LED flashing shortly)

You probably already know these steps, but we have to make it absolutely certain that it's a hardware issue, and not an issue with the thing you do :)
 

antrax360

Senior Member
Jun 16, 2011
181
9
0
How did you try to unroot? It's weird if you don't have working fastboot or flashmode, and without those, you're pretty much screwed. Those two should work even if you screw up big-time, like flashing a wrong kernel, but you must have done something weird if they stopped working?

And let me get this straight, you are pressing and HOLDING the volume buttons when you plug it to your computer, right? Make sure that the device is completely off by pressing and holding POWER + VOL UP. It'll vibrate a couple of times. Note that you're not supposed to be connected to the computer, since it'll then just boot again.

Then press and HOLD VOL UP for fastboot (blue LED), OR VOL DOWN for flashmode (green LED flashing shortly)

You probably already know these steps, but we have to make it absolutely certain that it's a hardware issue, and not an issue with the thing you do :)
I was going to flash the stock rom using flashtool right but everytime i tried to put the phone into fastboot mode it would go to the battery icon. At this point the phone was working fine. But no fastboot mode at all. Then i factory erased the phone through twrp. After that it doesnt boot up. Just sony logo no led lights. Even if i do vol up or down. Straight to the sony logo. Vol up plus power button, vibrates couple of times. I redo the process and it goes back to the sony logo.
 

Klaos3000

Senior Member
Sep 17, 2015
295
101
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I was going to flash the stock rom using flashtool right but everytime i tried to put the phone into fastboot mode it would go to the battery icon. At this point the phone was working fine. But no fastboot mode at all. Then i factory erased the phone through twrp. After that it doesnt boot up. Just sony logo no led lights. Even if i do vol up or down. Straight to the sony logo. Vol up plus power button, vibrates couple of times. I redo the process and it goes back to the sony logo.
The thing is that the screen shouldn't power on when you enter fastboot. The only thing that should go on is the blue LED. I don't use TWRP, and I don't know how it wipes stuff and if it only deletes user data, or if it formats the system. If it does the latter, then it literally wipes the system partition, making it empty, so if you ever format the system, you should flash a new ROM ASAP. A little late for that now though, but I'm still not convinced that fastboot isn't working.

ONE LAST TIME :laugh:

NOTE: The device should be disconnected from the computer.

1. Turn the device OFF by holding and pressing the POWER button and VOL UP. It should be disconnected from the computer by now. Got it? Nice.
2. Plug the USB-cable in the device first, since it's easier to plug it into the computer. Do not plug it into the computer yet. Only the Ultra.
3. Now HOLD VOL UP. Just hold it in.
4. Stick the USB cable, which is already inside your Ultra, to your computer WHILE still holding VOL UP.
5. The blue LED above the screen should light up now. The display should not power on or anything else. The blue LED is the only thing that should turn on.

Still nothing?
 

antrax360

Senior Member
Jun 16, 2011
181
9
0
The thing is that the screen shouldn't power on when you enter fastboot. The only thing that should go on is the blue LED. I don't use TWRP, and I don't know how it wipes stuff and if it only deletes user data, or if it formats the system. If it does the latter, then it literally wipes the system partition, making it empty, so if you ever format the system, you should flash a new ROM ASAP. A little late for that now though, but I'm still not convinced that fastboot isn't working.

ONE LAST TIME :laugh:

NOTE: The device should be disconnected from the computer.

1. Turn the device OFF by holding and pressing the POWER button and VOL UP. It should be disconnected from the computer by now. Got it? Nice.
2. Plug the USB-cable in the device first, since it's easier to plug it into the computer. Do not plug it into the computer yet. Only the Ultra.
3. Now HOLD VOL UP. Just hold it in.
4. Stick the USB cable, which is already inside your Ultra, to your computer WHILE still holding VOL UP.
5. The blue LED above the screen should light up now. The display should not power on or anything else. The blue LED is the only thing that should turn on.

Still nothing?
I have windows 8. I remember i had a hard time trying to get it into fastboot first time i rooted and unlocked bootloader. Just dont remember what i did to get it working.
 

NABENDU1

Senior Member
May 31, 2012
352
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MUMBAI
I have windows 8. I remember i had a hard time trying to get it into fastboot first time i rooted and unlocked bootloader. Just dont remember what i did to get it working.
Check whether the drivers have been properly installed in ur PC. If u can't get into flashmode try another system to flash the ftf. Procedure hold volume down while connecting the usb to plug. U will see a green led blink.
 

antrax360

Senior Member
Jun 16, 2011
181
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0
Oh! You probably haven't installed fastboot on your computer. Download and install, and try again.
Wooooohoooo phones alive jajaja. Thankssss. Though i got some more questions. First time i unlocked boatloader i was told to backup my TA files. what do i do with those now? I just flashed a stock c6806 unbranded rom. When i try to update the phone through settings it says it couldn't verify the update. i retried the process through sony companion app, and it says my phone is modded so it wont do anything.
 
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Klaos3000

Senior Member
Sep 17, 2015
295
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Wooooohoooo phones alive jajaja. Thankssss. Though i got some more questions. First time i unlocked boatloader i was told to backup my TA files. what do i do with those now? I just flashed a stock c6806 unbranded rom. When i try to update the phone through settings it says it couldn't verify the update. i retried the process through sony companion app, and it says my phone is modded so it wont do anything.
The TA partition is where your DRM keys are. It's a good idea to backup those keys in case you want to revert to complete stock in the future, or when you need to send it in for repairs. Unlocking the bootloader will remove the keys, but since your device was - weirdly enough, already bootloader unlocked, I don't think you even had DRM keys to start with, which is again, very weird.

No biggie though. Gone is gone. The reason why PC Companion told you that it's been modified, is because you're rooted, and it knows it, so you'll have to unroot before you update. That's only if you're updating through official channels, but you have a second alternative; Flashtool. It allows you to flash stock Sony ROMs, or FTF-files.

But you're saying that you flashed a stock 6806 ROM now, and that's what? 5.0.2? Why don't you just download the .368-update (Android 5.1.1)? Then you'll be on the latest version.
 

antrax360

Senior Member
Jun 16, 2011
181
9
0
The TA partition is where your DRM keys are. It's a good idea to backup those keys in case you want to revert to complete stock in the future, or when you need to send it in for repairs. Unlocking the bootloader will remove the keys, but since your device was - weirdly enough, already bootloader unlocked, I don't think you even had DRM keys to start with, which is again, very weird.

No biggie though. Gone is gone. The reason why PC Companion told you that it's been modified, is because you're rooted, and it knows it, so you'll have to unroot before you update. That's only if you're updating through official channels, but you have a second alternative; Flashtool. It allows you to flash stock Sony ROMs, or FTF-files.

But you're saying that you flashed a stock 6806 ROM now, and that's what? 5.0.2? Why don't you just download the .368-update (Android 5.1.1)? Then you'll be on the latest version.
I did unlock bootloader myself, TA file were backup. My phone is the 6806 model. The only ftf file i found on xda with a working link was for 4.2 jellybean. I just restored my TA files am going to reflash that stock rom and see what it says now.
 

Klaos3000

Senior Member
Sep 17, 2015
295
101
0
I did unlock bootloader myself, TA file were backup. My phone is the 6806 model. The only ftf file i found on xda with a working link was for 4.2 jellybean. I just restored my TA files am going to reflash that stock rom and see what it says now.
Well carry on then! :laugh: