[ZTE Z7, Z7 Max, Z7 Mini] pnin:
NOTE: this OP subject was originally "[HELP] ZTE nubia Z7 Max (NX505J) stock ROM v3.09 update report";

- for the "Upgrade to paolothlw8's Unofficial CM12.1 Lollipop v5.1.1 V3 report", see post #22.

- for the Stock v3.19 update, see post #4.​

I updated my Nubia Z7 Max from BB72's v1.64 custom KitKat 4.4.2 ROM directly to the latest stock Nubia v3.09, with Lollipop 5.0.

I want to leave here a brief account, so others know this can be done and it is not an overly complicated procedure. But, please, pay attention, because this will completely reformat and factory reset your device -- so, if you want to keep anything on the phone, backup before!

For starters, the downloads and instructions I used (mostly ;)):

Nubia Z7 Max v3.09 (free registration required for download)

http://www.needrom.com/download/nubia-z7-max-v3-09/

Be sure to access *#7678# dialer menu to enable both ports before and after flashing!​

Needrom instructions are quite detailed and accurate, so I'll just summarize the main steps:

Install ZTE mobile USB drivers. (I used 'Drivers All In One Tool By Tigreos')

Download and install 'Nubia Tool Updater V2.0.0' in your Windows computer.

Download 'NX505J_CNCommon_V3.09.rar' file on your computer and unpack.

Run the installed 'Nubia Tool Updater V2.0.0' as administrator (right click...) and select the path were you unpacked NX505J_CNCommon_V3.09.rar.

Watch Needrom's pictures carefully to know when you're ready to proceed (summary picture below, you might need a few tries...).

The remaining button is "Open"......

My findings:

- Drivers MUST be updated for this to work, so you'll have to uninstall previous versions;

- The phone must be connected to computer in powered state, before the Updater is run;

- I had two hiccups after installation, because (I thought) the phone didn't boot and got stuck in the Chinese red letters after the boot animation;

- I solved this by connecting phone to computer again, a Chinese message with a counter appeared, and I let it finish (it counted to 21);

- Tigreos tool also provides for TWRP v2.8.6.0 quick installation (reboot required);

- TWRP provides ROOT (reboot required);

- Even after rooting adb doesn't push files (system RO, no ROOT in shell), so I needed an SD card to get GApps on phone;

- This is caused by ROM being a production build (you'll get a message saying thus: "adbd cannot run as root in production builds");

- After you flash GApps via TWRP, setup and get updated busybox from the Play store, as well as [THREAD="1687590"]adbd-insecure[/THREAD] to solve the problem;

- Not all languages are present (I use English) and some features will be presented with Chinese characters -- so, for a smoother experience, some tweaking will be required...

All in all a fast and stable new start for this great phone, which is being let down for the lack of Western locales support.

Bear in mind that various other information sources exist here at the forum, as well as elsewhere; I'll just list a couple here for the benefit of newcomers...

[THREAD="3053880"][Tutorial] [Root] [Upgrade] [4.4-->5.0] ZTE Nubia Z7 Max to Lollipop 5.0[/THREAD]

Very detailed report by user craagz of the upgrade procedure from stock v1.57 (KK 4.4.2) to v2.13 (Lollipop 5.0).

[THREAD="3100542"]Tuto installation rom stock v 3.09 nubia z7 max[/THREAD]

French(!) tutorial by user hayastan06 of installation of the stock ROM v3.09 (Lollipo 5.0)

For further info on the Nubia Z7 Max, search the present Nubia forums (http://xdaforums.com/zte-z7) or check my dedicated index post ([THREAD="2961145"][INDEX] ZTE nubia Z7 Max[/THREAD]).