Nokia 3, 5, 6 & 8 Official Firmware flashing tool is Known as OST ( Online Service Tool) .
Nokia 3 Firmware :- https://mega.nz/#!RAlVHJJC!9o0Ntn0GG...jIcQJ_f-V1eJGc
Nokia 5 Firmware :- https://mega.nz/#!Qd0GwLYa!lQ4owEX37...h1T0iPiaFpv6_E
Nokia 6 Fimrware :- https://mega.nz/#!5ccRnb4b!VsgiKQ4Cj...TnEz0FA_FMZQbM
New Link for all Upcoming firmware's
OST tool & patch
Download OST LA v6.0.4:- https://yadi.sk/d/hkDVImee3NAZ7a
Download patch :- https://yadi.sk/d/Tm2MvTJs3NAZy2
password for patch :- 123
Many thanks to @Quixote78 for the OST Tool patch and the instructions ( which is posted in Nokia 6 forum)
1. Download original firmware from the above link
2. Download OST LA v6.0.4
3. Download patch
4. Unpack OST LA with 7zip and install on your PC
5. Unpack patch (password :- 123)
6. Replace . exe file OnlineUpdateTool with an exe file OnlineUpdateTool exracted from the patch and delete OnlineUpdateTool.exe.config in a folder C:\Program Files (x86)\OST LA (see pic.1 )
7. Unpack software with 7zip.
8. Start patched OST LA from the above mentioned folder by double left-click on exe file incicated on pic2.
9. If everything is alright the program will run without requesting login and password to hook up with a server.
10. Select the original software.
11. Enter your Nokia 6 into Download mode connected with USB cable to your PC.
12. After your device enter into Download mode, the button Edit Phone Information will be available. Push that button and wait for a error (something like failed to reboot to FTM mode) being appeared. Don't be so tragical about it. Press OK and see the button Next should be activated..
13. After button Next become active, press on it and and have an eye on the flashing process or have a cup of tea not to kill time.
14. Your device will reboot and you may congratulate oneself.
Firmware supported for below Nokia 3 Supported Models
- NOKIA 3 TA-1032 DS
- NOKIA 3 TA-1020 SS
- NOKIA 3 TA-1028 SS
- NOKIA 3 TA-1038 DS
Firmware supported for below Nokia 5 Supported Models
- NOKIA 5 TA-1053 DS 16GB+2GB
- NOKIA 5 TA-1024 SS 16GB+2GB
- NOKIA 5 TA-1044 DS 16GB+2GB
- NOKIA 5 TA-1027 SS 16GB+2GB