[Lenovo ZUK Z2 (Plus) Guides, News, & Discussion] mGforCe:
I accidentally restored TWRP backup of another Zuk Z2 phone on my new pgone and in this process over-wrote the EFS partition. This left me with a phone having no IMEI, no mac for Wifi and Bluetooth. Effectively No Network on phone.

Worried, I searched across internet to find out ways to restore IMEIs and get my phone working again. The way out was to restore xqcn file and use it to get back IMEIs, mac address etc. But there were various posts and mixed feedbacks. Even when I restored modified xqcn and got IMEIs back, it had only one sim actually working and other had no signal.

I spent many hours searching for finding right steps. It was a long tiring process wherein close to 2 days were gone trying multiple methods, flashing QPST roms around 10 times to observe network in Stock ROM , in Custom ROMs and after reflashing etc etc etc . Shouts go out to Akrapovic & Nordicus for their detailed posts which helped me in understanding lot many things and also finalizing key steps to restore IMEIs, MAC etc and getting phone working

Pre-requisites:

1) QPST installed on PC; Download v 2.7.453 from here or elsewhere if you know of

2) ADB / Fastboot installed

3) Drivers Installed for Zuk Z2

4) Hex Editor to edit xcqn file

5) WriteDualIMEI_W_G_eMMC - to write IMEIs once xqcn has been restored

6) Zuk Z2 rooted with ADB enabled through developer options and connected to computer

For points 2 and 5, pls refer here to download the files and tools.

So the solution which worked for me, and one which has been tried and tested is following:

1) First check the IMEIs dialing *#06#.

If you see IMEI and matching with that on your box, there is no issue and you should stop.

If you see blank / error, process further

2) The EFS is corrupt and hence we don't see IMEIs. Follow this paget and get the EFS partition wiped out to properly prepare EFS for restore of xqcn in next steps.

I had restored xqcn file without wiping EFS partition and later on had issues. But all these issues were gone when first wiped EFS and then restored xqcn. So will suggest doing same.

3) Get the xqcn for our phone Zuk Z2 from here original credits to 唐大土土 and Nordicus who shared it here

Use HexEditor to search below default values and replace them with your devices value. IMEIs / MEID is available on box. MAC can be assumed suitably

MEID: 22 22 22 22 22 22 22

IMEI1: 33 33 33 33 33 33 33 33

IMEI2: 44 44 44 44 44 44 44 44

WIFIMAC: 55 55 55 55 55 55

BTMAC: 66 66 66 66 66 66

4) To be on safer side and avoid other variabilities, it is suggested to first flash QPST rom to ensure that apart from EFS all other partitions are fine. This is optional.

5) Now with rooted phone connected to PC, open command prompt on PC and go to adb folder. From there type these commands

adb shell
su (looking at the phone screen, as during this second command you need to grant root rights)
setprop sys.usb.config diag

Once done you will see in device manager 3 new com ports are open. If some errors or no success in getting com ports opened you can try following too

adb shell
su (looking at the phone screen, as during this second command you need to grant root rights)
setprop sys.usb.config diag,rmnet,adb
setprop sys.usb.config diag,acm_smd,acm_tty,rmnet_bam,mass_storage,adb

6) In Device Manager, you will see a com port title Qualcomm Android Diagnosis etc, note the com no.

7) Open QPST, click "Add new port" and enter the port in both places (Port and Port Label), which is written in the device manager.

Next Click Start Client -> Software download. Go to Restore tab, and use the modified xqcn file which you saved in step 2 and press Start.

If any error, tick the check box "Allow phone/file ESN mismatch" and press Start

8) Once restore is 100% done, close the QPST and open the WriteDualIMEI_W_G_eMMC, and put in the IMEIs and flash. You should see Green Pass.

9) Reboot phone and dial *#06# - the IMEIs should be seen. Bingo, job done... give me thanks. Just put in SIM and network should be back.

For Step 7, if more details required, pls refer this post with step by step details

Hope this helps !! I will be extremely happy if this guide helps you in restoring IMEIs, repairing lost network and radio issues.