Bootloader unlock allowed: No

[Jo1956]

We recently bought a Xperia Z4 Tablet. The service menu says Bootloader unlock allowed: No and I assume the usual procedure to open the bootloader did not work because of this. What can I do to change Bootloader unlock allowed: No to Bootloader unlock allowed: Yes? We need root access for the device. It is a university device for field work and the decision for SONY was because of the good support for developers. Without root the tablet is of little use. Any suggestions? Thanks in advance! Jo

[Uliwooly · Accepted solution]

Nothing, your carrier / network, requested the bootloader to be locked and there's nothing that can be done, other that replacing the motherboard, which will cost almost as much as a new device.

On a side note, why do you want to unlock the bootloader?

[Uliwooly]

Just realized something, the tablet belongs to the university and unlocking the bootloader will void any warranty also some apps and services will no longer work, and the DRM keys will be gone forever.

This part it's my opinion, I can't see any reason to unlock the bootloader other than use the tablet in a way that the University doesn't want you to use it, the solution buy an unlock tablet and you'll be able to unlock the bootloader, but do tell us why is it necessary to unlock the bootloader and or root the device?

@Jo1956

[Jo1956]

Thank you for the clarfication. I did not get the device through a phone company and there is no SIM lock. May be it would have been better just to have the WiFi version of the Z4 without LTE.

Why root?

To access the VPN (cisco) of the university a proxy needs to be used. I did not find a working (non-root) app yet which can do this. Any suggestions since rooting the device is no option because of the looked boot loader? 

[steamer360]

To be honest Uliwooly, it isn't your business why anyone should want to root or unlock their bootloader. It is entirely their decision.

On a bit of a tangent, I can just see the absolute  that will ensue when Sony decides to shut down its mobile division, leaving all of these "bootloader unlock allowed: no" devices any way to update to the latest most secure version of Android. To me, hardwiring a bootloader lock into a supposedly developer friendly device is completely moronic, and is definitely not "developer friendly" as Sony claims themselves to be.

Also, I would rather have someone who works for Sony answering these "bootloader unlock" threads, as they probably have a better understanding of the process and limitations than you, Uliwooly.

[Lord_viridis]

Point uliwooly was correctly making...
It's sod all to do with Sony, it is the network or vendor that has requested the loader be locked.

[Jo1956]

I actually decided for Sony because of the good support for developers which I read in other forums. I like to control my devices myself, e.g. by using, cyanogenmod. The divice is not a branded device. It is a totally SONY issue and I am too would like to hear directly from SONY why they decided to lock the device.

[Lord_viridis]

You purchased it direct from Sony?

[Jo1956]

Hi Viridis,

not directly from Sony but through a harware vendor. No mobile phone company is involved and there is no branding.

[cchristofis]

I had the same issue with the locked bootloader. Have you got the "my Xperia" app enabled? If so, try to disable it and enter the Service Info to check the bootloader unlock status. Mine has changed to "Yes". I actually managed to fastboot a custom img file but I can not enter recovery mode in order to install superSU.