Hi dude I have one of those phablets from Sprint. It came with 3.2.1 Android OS.
XDA has some custom roms to upgrade it but their guides sucks.
(I don't know maybe they think everybody is a focking nerd. And is hard to understand what they are talking about lol hahaha).
Here what I did to upgrade the phablet. ZTE v55 (q78-v55)
1. You need make a backup of your phablet OS.
-- 1 Download and unzip the last ADB from google.
Also at the same website download the drivers.
-- 2 search and copy the CMD.exe from you PC Windows at the same place where you put the ADB. (my case it's at platform-tools folder).
-- 3 Download and unzip TWRP 2.6.0.0 for v55 from XDA and copy it at the same place of ADB. (also rename it with a easy name to type it. In my case 1.img)
-- 4 Put a micro SD card in card slot of the phablet to save the backup.
-=Process=-
-- 5 connect the phablet to the PC Windows.
-- 6 open CMD.exe as admin (right click then run as administrator).
-- 7 Recovery Mode; with the phablet off. Press power button to turn it on and release the button, and when you feel the shake, press volume up (vol +) If you do it well, you will see a black screen with an white Android robot with some letters in its stomach FTM and a blue light blinking next to the front-cam.
-- 8 Now on CMD.exe, type "adb devices" without quotes. You will see the name of the phablet at the list.
-- 9 Now type "adb reboot bootloader" if you get success, you will see how the phablet turn off-on automatically also shake. But now the phablet gets a black screen with nothin blinking. Now your phablet is in FASTBOOT MODE.
-- 10 As in fastboot mode, Now type "fastboot boot <name of you twrp img>" In my case I rename it as 1.img (step 3) so for me I'll type "fastboot boot 1.img". If you get success your phablet turn off-on and will reboot at twrp image.
-- 11 Now at the main menu of twrp tap with your finger on "backup". Check with a X all the boxes that you are interesting to save. Tap on "storage" and select the Micro SD (sdcard-ext). Then slide the arrow to start the back up.
It was easy hee? focking guides of XDA make easy things hard, bah!! but now for me it was so hard to upgrade the OS. why cuz the focking guide didn't explain about the google apps and what they do, and why you need install them to make those custom roms work well.
At XDA they put these custom roms:
PAC 4.1.2
ParanoidKANGdroid (4.2.2)
CM10.1 4.2
CM10 4.1.2 <<<< I recommend you this one.
Why 4.1.2 CM10 cuz is simple doesn't come with 5h!7 and is clear to use, also is faster. Also come with flash player and works well, and has code videos to watch HD videos and works faster with no delay.
But none of those roms come with the driver cam (back and front). So thats why you need make a backup in case you want back your cam work again.
Android 4.2.2 is slow, flash player doesn't work for me, and code videos doesn't come at the rom, so I tried to install them but work too slow and has delay with the sound. If you make it works well please feel free to tell me and I'll try it.
2. Now Upgrading the phablet.
-- 12 Same process from 5 to 10.
-- 13 Now you need the roms, at XDA you can find them in format ZIP. Copy them at your Micro SD as zip.
-- 14 Now here is what those smart guys didn't explain you; You need download the google apps to use those roms, but you need download them according of the version of Android OS you put it. Search them under the name "google gapps" download them and copy at the micro-sd as zip.
If you want Android 4.2.2 then you need google gapps 4.2.2
If you want Android 4.1.2 then you need google gapps 4.1.2
Be sure, when you download them, they are as "ZIP" format.
-- 15 Now you should be at the main menu of twrp, (steps 5-10) now there tap with your finger on "install" tap on "storage" select "sdcard-ext" then "ok".
--16 At the right side, you should be see a list with the file names you put it in the micro-sd card, so select the rom (Android OS) you want to install.
Now just slide the arrow to start the installation.
-- 17 Now when it finish, go back to "install" and select the "google gapps" file and install them.
-- 18 once it finish turn off the phablet, now you need clear the cache and user data.
Press power button and when you feel the shake, press volume down (vol -) Now you should be at the factory "android system recovery utility". Well that in case you didn't flash the recovery partition yet.
Why there? cuz with the twrp utility, in my case didn't work and when I tried to turn on the phablet this get frozen, sometimes get a infinity loop.
So, my solution was. CLEAN THE CACHE, and the user data from the factory "android system recovery utility"
With the buttons vol + - wipe (data/factory reset) and (cache partition).
If you get succes, just turn off-on the phablet and that's it.
Benefits:
Now you are enabled to play Clash of Clans, Bomb Beach, other games and apps that require a most recent android OS.
Cons:
Front and Back cam don't work.
WiFi get stuck at the first time, just turn off-on the device, not be afraid.
Phone function doesn't work any more, need restore the backup.
Hope this mini guide helped you, and others find it useful.
Why no LINKS?
I don't know the rules of this forum, and I don't know if moderators want let me do it.
Please credits by Me lol
WarSxNes
------- Thanks to READ