Hi,
Since the 20170425 release of Android 7.0 tends to lock the bootloader on this phone, I thought it would be interesting to share the files that can boot it without locking your bootloader.
The preloader and lk are from previous release of Android 7.0.
Instructions:
1. Download this ROM: https://www.needrom.com/download/doogee-y6-7-0-2/
2. Download the fix above
3. Extract both files with WinRAR or 7zip
4. Go to the extracted ROM folder and delete these files: preloader_hct6750_66_n.bin , lk.bin
5. Copy everything from the extracted DOOGEE-Y6_Nougat-FW folder.
6. Paste them in the extracted ROM folder and replace the existing ones!
Make sure that you replaced the existing files!
7. Open SP Flash Tools and load the scatter file.
8. Choose "Firmware upgrade" and click "Download".
9. Power off your phone
10. Connect it to the phone with USB cable.
Flashing process will start.
Wait till the end. You'll see a big green button saying "OK".
11. Disconnect your phone power it on.
12. Done.