Virtually impossible to unlock bootloader

[B!GBOY]

I just share my experience in case it helps someone.
I received my phone yesterday and got frustrated too as there was theoretically no way to unlock it without using magic or hardware mode . the unlock tool is practically broken.
Here is how i made the cable:
as I didn't want to destroy the new fancy usb c i used an old otg cable and a normal micro usb. (you can use a usb extender too)
I cut both in half and connected the USB A part to the female USB A part (from otg cable) . solder same color cables to each other. isolate red and white (we dont need them) and just let black and green out.
in case yours is a different color, black is the ground, green is the second pin from left on the type a side.

there is a problem with the latest version of mi flash so i had to use the old beta version.
downloaded drivers from here
and got the china dev recovery rom from here

install mi flash and both drivers and extract the rom folder.
turn off your phone connect the cable to your pc (male side) and connect the black and green together with your finger then connect your phone using it's normal usb c cable to the female part of the cable we just made. and after a couple of second let black and green go (separate them) now if you press refresh in miflash you should see your phone's com port and can flash everything normally.
so flash the china dev rom, and sign in with your account.
after that you can unlock without any problems

 

[manieq14]

Hi!
I had the same problem 3 days ago. But in my case in deep flash mode I had error: "cannot receive hello packet" or sth like this. I changed drivers in "devices manager". There is a list with optional drivers. I changed that and then everything started without problems.

 

[Mois1234]

I just share my experience in case it helps someone.
I received my phone yesterday and got frustrated too as there was theoretically no way to unlock it without using magic or hardware mode . the unlock tool is practically broken.
Here is how i made the cable:
as I didn't want to destroy the new fancy usb c i used an old otg cable and a normal micro usb. (you can use a usb extender too)
I cut both in half and connected the USB A part to the female USB A part (from otg cable) . solder same color cables to each other. isolate red and white (we dont need them) and just let black and green out.
in case yours is a different color, black is the ground, green is the second pin from left on the type a side.

there is a problem with the latest version of mi flash so i had to use the old beta version.
downloaded drivers from here
and got the china dev recovery rom from here

install mi flash and both drivers and extract the rom folder.
turn off your phone connect the cable to your pc (male side) and connect the black and green together with your finger then connect your phone using it's normal usb c cable to the female part of the cable we just made. and after a couple of second let black and green go (separate them) now if you press refresh in miflash you should see your phone's com port and can flash everything normally.
so flash the china dev rom, and sign in with your account.
after that you can unlock without any problems

THANK YOU!
This worked perfectly. Really good, short and understandable explanation you have written.
The only thing I stumbled upon is that you have to connect the usb, touch/release the 2 cables and flash really fast. Now I have a unlocked and rooted phone.

 

[shamllakh]

Follow the guide that I posted to make the cable(first link), install all the drivers and software needed (second link).
After successfully putting the phone in deep flash mode you need to update Qualcomm drivers (under device manager it must appear as com3 or com10 port after that).
Then use Mi Flash tool to flash Chinese dev rom (http ://bigota.d.miui.com/7.1.20/miui_MI5S_7.1.20_229fa68558_6.0.zip). If the flash fails the first time reboot the computer and try again.
After that sync connect your MI account to the device, enter Dev mode and you will find OEM Unlock option.
Not easy but it works.
Good Luck!

Thanks for help.
One question: For this to work, is it required to have the "unlock permission sms" received before steps you mentioned?
Thanks again.

 

[ka3yal]

Thanks for help.
One question: For this to work, is it required to have the "unlock permission sms" received before steps you mentioned?
Thanks again.

Yes, you need it to complete the last step of unlocking process.