[GUIDE][G,U,Ch] DFU Unbrick Guide - Disassembly

[Choose an username...]

DFU Unbricking Guide - When nothing else works
​

Heads-up: Now this guide is not the only way forward - EDL Tool has an integrated function to get out of DFU, and MultiDL (zte's tool) also works if you prefer MiFlash.
It is possible that you might still need to do a testpoint procedure to get into EDL. ​

4th category brick – phone status which does not allow to boot into next modes: Recovery, Fastboot, FTM, EDL. In Windows Device Manager the phone detects as ZTE Handset Diagnostic Interface(DFU) (COM...) whrn you connect it via USB cable. Any of possible manipulations give the same DFU mode (even when you force to install Qualcomm HS-USB QDLoader 9008, in reality it is still a DFU mode).

This guide is based off of @Vick78 's 4th Category Brick Repair Manual. I had to follow the guide in mid-April, and after doing it I realized that rewriting the thread would help all of us.
Please thank Vick78 on the other thread. I've been endlessly sending people there to fix their phones, and it works like a charm.

All of this is at your own risk, however obvious that may be... If you don't think you can make it, take it to someone experienced and show 'em this guide.

Patience is key! Be really careful when doing this, or you can break something inside and lose functionality. Flex cables are awful.

0) Know your Model:
Turn your phone around and see what model it is. If you screw up and flash another model's ROM you can lose your IMEIs.
In some cases (AliExpress) the phones come with A2017G software even though they are A2017 models. Just beware.

1) What you Need:
• A Windows PC with (preferrably) 64-bit support. Win7 will do, although Win10 may make stuff slightly easier. If it is a tower PC, use the rear USB ports, not the front ones!
• Your corresponding FULL_EDL package. Download it from @WesTD 's Latest Stock ROMs thread. (Thank him too! :good
• MiFlash. Get it from Yandex or Mega, same file. Thanks @djkuz for the link.
• Metal paper clip or needle to short circuit the test point.
• Tiny Phillips screwdriver or at least a knife, to get the screws off.
• Stock USB cable, or at least one that works good with data transfer.

2) Disassembly Video
JerryRigEverything made a full teardown video. Watch the teardown part a couple of times (up to 3:40) until you're familiar with the parts. You don't have to take the speakers or the USB-C module off though, just keep them there.


3) Teardown Hands-On
Images are also from Vick78's thread.
Make sure that the phone is completely off before starting! Also take the SIM card tray off before separating the screen from the back housing or you'll break something

a) Take the speaker grilles out by prying on the edges. You don't need a heat gun for this. Remove the black material to expose the screws, but be careful not to break it if possible, because it protects the speakers.


b) Remove all the screws and VERY CAREFULLY separate the screen from the back housing, to avoid breaking the FP sensor's flex cable. After that, disconnect the FP cable with your nail or some preferably non-conductive thing


c) Take the protective metal piece out, then disconnect the battery, USB-C and display/power connector, then get all those screws out. Put them somewhere so that you won't lose them (piece of tape, maybe a magnet).


d) Take the motherboard out and disconnect the antenna wire that's below it, on the lower part.


e) Disconnect the rear camera. Leave the front one connected.


And now you can see the TEST POINT that you have to short


f) Since the testpoint is in the back of the motherboard, and you need to have the battery and USB-C connected, I advice you to pry the battery off. You can rupture it very easily though. If you don't want to do it, don't worry, it is possible to make without taking it off, but you might break a flex cable and, honestly, it's much harder to hold the connection on the test point while the mobo is facing downwards.
If you will pry out the battery, be REALLY careful and don't force it.

g) Put the motherboard with the test point facing towards you. Connect the battery and the USB-C module to it, and the USB-C cable to the USB-C module (But NOT to the PC yet!). Be VERY GENTLE with the "little lego connectors" as I broke a couple of pins from the USB-C connector (It still works fully, I believe they have redundant pins in case someone like me screws up)


4) Connection to the PC

Before flashing, we need to make sure that the drivers are the correct ones.
- Open Device Manager (if on win10, right click on the start menu button and select device manager), find "Ports (COM & LPT)", and open it. Leave Device Manager open for now.
- Find an USB port on your PC that you can reach while you short circuit the test pad. If you have a desktop PC, it has to be one of the rear ports (NOT the front ports, those have a lot of interference) and they should be USB 2.0 if possible.
- Take the clip and connect the test pad to the big chunk of metal that's right beside it:

-Insert the USB cable (previously connected to the phone) to your PC's USB port.
-Watch Device Manager now. The phone should appear as "Qualcomm HS-USB QDLoader 9008". If it does, just go to the next point. If it doesn't, see if it is called "QUSB_BULK" under USB devices (This happens if you used Zadig). If this happens, find the QUSB_BULK device, right click, Uninstall device, Delete the driver software for this device. After that disconnect the cable from the PC, disconnect the battery, and connect it again; and redo the clip thing up to this point. The correct driver should install itself.


5) MiFlash

- Open MiFlash, keep it ready
- Unpack the FULL_EDL file to a folder with the same name, then open the folder and make sure that the files are directly there (i.e. they aren't inside another folder), put it somewhere, and select it from miflash ("select" button, select the folder).
- Hold the connection with the clip, as stated in the image above
- Click on Refresh from MiFlash, as soon as it detects a device hit "flash"
- If all goes well, it should say "send configure command". Wait 3 seconds and get the clip out. If it doesn't get to this part or if it fails, just disconnect it from the PC, disconnect the battery and reconnect it, and try again. Do this until it succeeds and it flashes. You might need to do this more than 5 times! If it doesn't work, try leaving the test pad connected for more or less time, like 2 seconds, 2.5 seconds, 3.5 seconds, 4 seconds... But 3 seconds works for most.
-If the flashing works, once it ends, go to the recovery and factory reset the phone. Otherwise there might be conflicting information in /data.

 

[WesTD]

actually you don't need to open your phone. I was same situation and made a deepflash cable. it needs a little electronic ability and passion. you can enter edl mode with this method but it is too hard and you must be very patient.

I got edl mode one time but miflash didn't install correctly stock rom and couldn't again. @asderdd helped me and my device is okay now.

 

[Choose an username...]

actually you don't need to open your phone. I was same situation and made a deepflash cable. it needs a little electronic ability and passion. you can enter edl mode with this method but it is too hard and you must be very patient.

I got edl mode one time but miflash didn't install correctly stock rom and couldn't again. @asderdd helped me and my device is okay now.

The deep flash cable works only sometimes. I didn't try but most people bought a bunch of normal ones and they didn't work

 

[andrizmitnick]

@Choose an username... bro should I take out the daughter board (which held usb c port) too? what should I do about the usb c module u've mentioned above?

 

[Choose an username...]

@Choose an username... bro should I take out the daughter board (which held usb c port) too? what should I do about the usb c module u've mentioned above?

It's not necessary, just taking out the board and the battery is usually enough. Be careful with the USB-C flex cable though, those are fragile

 

[DrakenFX]

just my 2 cents here, better off getting cable like this

https://www.amazon.com/gp/product/B06XXCLMGM

bought one just to have one in any sort of emergency and even tested and works like a charm and is not just for ZTE devices but any snapdragon device out there....

 

[andrizmitnick]

It's not necessary, just taking out the board and the battery is usually enough. Be careful with the USB-C flex cable though, those are fragile

I ended up taking out the daughter board, I got it working on my 2nd try. my axon is working fine now, thank u so much for the guide, really helpful for urgent situation like I had atm ?

edit: I forgot to ask, do u know any solution on how I can recovery my bootloader mode back? I already try flashing official rom from stock recovery but no luck.

just my 2 cents here, better off getting cable like this

https://www.amazon.com/gp/product/B06XXCLMGM

bought one just to have one in any sort of emergency and even tested and works like a charm and is not just for ZTE devices but any snapdragon device out there....

i'm too lazy to wait, so today i'm following this guide and it's a success. thanks btw for the link, gonna order it next week for future needs

 

[Miustone]

Will try this, my Axon 7 is still bricked af. Can't boot into Recovery, Bootloader, System or anything else without Reboots. Hope this Guide does the Trick...

 

[Choose an username...]

Will try this, my Axon 7 is still bricked af. Can't boot into Recovery, Bootloader, System or anything else without Reboots. Hope this Guide does the Trick...

And? Did you manage to pull it back together?

 

[bornlivedie]

I have my Axon 7 since March 2017. After a month of owning it, when Android 7.0 was released, I rushed to flash a chinese rom. The result, a nice brick.

I tried with 3 EDL cables and shorting that pin, many many times. No luck. So back then I decided to put the phone back in its box, forget about it and move on. So eventually I purchased a new phone, wich I hated so much because it was more expensive than the Axon 7 and lacked in every aspect. So I sold it as well, and bought another phone, which I loved, but again, lacked in comparison to the Axon 7, until I was mugged. So I remembered that I had an Axon 7 lying around in its box, and decided to search XDA for a solution. That's when I found this thread and I decided to try and revive the phone.

All can I say is thank you. You brought my beloved Axon 7 back to me.

Thank you so much.

 

[Harmtan2]

Thanks for the Guide! Annoyed at myself for my bonehead move that got me here in the first place, no biggie though as I used to repair phones for a living. If was any good with solder, I'd contemplate sticking a dab on that pin and never worry about not getting into EDL Mode again. I really like this phone, but the crap they've pulled in making it a nightmare to tinker with has me not desiring to get another one ever. OnePlus will probably get my next dollar set cuz of how open they are currently.

 

[Choose an username...]

Thanks for the Guide! Annoyed at myself for my bonehead move that got me here in the first place, no biggie though as I used to repair phones for a living. If was any good with solder, I'd contemplate sticking a dab on that pin and never worry about not getting into EDL Mode again. I really like this phone, but the crap they've pulled in making it a nightmare to tinker with has me not desiring to get another one ever. OnePlus will probably get my next dollar set cuz of how open they are currently.

i don't think that would be a good idea. your phone would probably ONLY enter EDL mode. But I thought seriously about soldering a pushbutton on it. thing is that if you somehow rip the pad off, your mobo is dead.

 

[Reyad_W_K]

Thank you for this guide my phone is working on chinese rom now but the big problem is
i cant flash any thing now .
vol up + pwr then the fastboot keep restart
vol up + vol down + pwr send me to dfu mode
vol down + pwr send me to ftm mode and when i send (( adb reboot edl )) i get qualcomm usb but mi flash keep say (( can't receive hello packet )) i tried many many times with 3 versions of mi flash but nothing works
please help me i cant live with chinese rom .

 

[Oki]

Thank you for this guide my phone is working on chinese rom now but the big problem is
i cant flash any thing now .
vol up + pwr then the fastboot keep restart
vol up + vol down + pwr send me to dfu mode
vol down + pwr send me to ftm mode and when i send (( adb reboot edl )) i get qualcomm usb but mi flash keep say (( can't receive hello packet )) i tried many many times with 3 versions of mi flash but nothing works
please help me i cant live with chinese rom .

Try Flashing with the Axon 7 EDL Tool. The problem can also be the EDL package you are trying to flash. Try now a different one. If you can get to EDL mode, then it should work.

 

[Hylex]

Woke up today to see my phone not turning on. Having troubles booting up and when I choose to go to recovery or fastboot through the unlocked bootloader warning menu it just bootloops. I connect my phone to my PC and it is already showing the "Qualcomm HS-USB QDLoader 9008" in device manager. Do I still need to open my phone and do the paper clip test in Step 4? Or can I continue on with the rest of the guide?

 

[Choose an username...]

Woke up today to see my phone not turning on. Having troubles booting up and when I choose to go to recovery or fastboot through the unlocked bootloader warning menu it just bootloops. I connect my phone to my PC and it is already showing the "Qualcomm HS-USB QDLoader 9008" in device manager. Do I still need to open my phone and do the paper clip test in Step 4? Or can I continue on with the rest of the guide?

You should be able to just connect and do the final part. As long as your emmc is all right, of course

 

[Hylex]

Thanks for the quick reply. Heh, how often is flash storage failing a problem with other users? =X

 

[Choose an username...]

Thanks for the quick reply. Heh, how often is flash storage failing a problem with other users? =X

Maybe I've seen it once, but i'm on the q&a section all the time, so it's extremely rare. If it tries to boot then maybe it's just something much simpler

 

[TysonBeall]

From FTM mode ( hold volume + and plug in USB cable) adb should be enabled. If the phone has a Qualcomm chip and Qualcomm drivers have been installed on your computer. Use "adb reboot edl" to reboot the phone into edl / Qualcomm 9008 mode. No need for cables or tearing the phone apart. This does not work on every phone.

Sent from my SM-G935V using Tapatalk

 

[Hylex]

You should be able to just connect and do the final part. As long as your emmc is all right, of course

Successfully flashed B35 EDL. Phone is unresponsive to any power or volume key presses. MicroSD card is removed. Still no cigar. Can't get the phone to be recognized as EDL mode anymore either. Phone detected with different USB port for EDL. Flashed again. Still nothing. Any suggestions? I still have the option of taking the phone apart, but that is a last resort if that makes the ability to RMA void.


I can feel the phone warming up when I plug it into a charger. That's the only sign of life I see in the phone.