Check in Windows device manager whether a Preloader COM port appears for a few seconds after connecting your powered off phone to USB. You might need to reinstall the drivers.
Hi,
Thanks for that tutorial that helped me recovering my IMEI numbers lost on an UMI Z after upgrading to N.
By the way, I've apparently lost my serial number as what the phone shows now looks auto-generated : 0123456789ABCDEF
Does this tool work on recovering that SN number (there's a pic showing some ESN write option in the tuto) ? What should it look like on the box sticker ? I can see a lot of numbers but don't know which one could be the serial number of the phone.
Hi,
The SN Write Tool is able to permanently change/recover the IMEI numbers by writing the nvram partition. Android apps can't do that since the nvram partition cannot be accessed from Android - it contains raw data, not files in a filesystem. Your solution is just a temporary one that saves the changes on the userdata partition, so after a factory data reset you'll lose your IMEI numbers again.
Same thing happened to me, got this S/N 1234567890ABCDEF. Anyone facing this or knows how to fix it ? Warranty will surely be void if I can't recover a proper S/N
Hexabitt replied at 2017-8-2 06:26
Hi,
I have got an UMI eMax.
I formated the whole flash except bootloader to earase the nvram partiti ...
Hi,
Under point 10 in the tutorial:
''NOTE: If the process gets stuck at this point what the screenshot shows above (switched to META mode), disconnect the USB cable for a few seconds, then reconnect it and the process will continue.''
Worked fine for me. Have UMI Z and erased my IMEI when trying to flash latest NOUGAT update, which doesn't work for me (puts phone in bootloop). Downgraded back to V7.01_20170601 ROM and used tool to restore my IMEI numbers. Only thing is that I didn't select the Wifi address on page 3 because it wouldn't autogenerate a number. As my wifi was working perfectly I decided not to change what was in the phone, and everything worked out.