It seems that the original version installed was something like "rk3026-eng 4.2.2 jdq39 eng.liufeng" and kernel was 3.0.36+ #415. I've figured out doing some Google research for this model.

Oma7144 said
Without the genuie kernel nearly no chance. Sorry.

- Oma -

Theres no way to compile a new one if I try to know which specific hardware uses this device? I used to think that this kind of cheap-chinese devices were a clone each one from another or at least that they were using the same PCB board. I beg you pardon for my poor knowledgement about this but why is so difficult to solve that? Thanks again.

PS: The complete string of the original kernel from this tablet is: rk3026-eng 4.2.2 JDQ39 eng.liufeng.20140624.153913 test-keys.

Oma7144 said
Unfortunately we do not have kernel sources nor a defconfig to build a kernel. You will also not find out exactly which hardware is in the tab. In this price class it is most likely that every batch has other hardware components. So, when the genuine kernel is gone the game is over.

- Oma -

Well, I've doing some good progress with that. I've been able to get back to life this tablet using this firmware I found on the web and flashed with RKBatchTool:

原道N70S-FZ_RK3026_8931_8188_6225_F120d0309_B120d0309_1680_1024x600_4.4.2_20140531.rar

This seems to be the stock ROM for Vido N70S. Maybe I can use [ ROM ] Vido N70S Android 4.4.2 KitKat custom root firmware (2014/05/17)??

The device boots and works really fast but front 0.3mpx camera and gyroscope don't work. Audio, WiFi, Touch, SD, brightness, button controls... everything seems to be working well. Is there something we can do to make camera and gyro work?

Thanks again.

Oma7144 said
Great. No rotation or just wrong orientation?

You can try this build with the FZ kernel: http://www.arctablet.com/blog/forum/crewrktablets-rk3026-entwicklung-und-customroms-development-and-croms/rom-vido-n70s-android-4-4-2-kitkat-custom-root-firmware-20140517/

- Oma -

No rotation. Image fits perfect on the screen but landscape only.

When opening the camera App an error message appears warning that no camera is found.

Oma7144 said
You are a lucky guy! We need some parts from the Android which will work for you. So pls flash other KK builds from here (together with the N70S-FZ kernel) to see if cam or sensor will work.

- Oma -

Tested this http://www.arctablet.com/blog/forum/crewrktablets-rk3026-entwicklung-und-customroms-development-and-croms/rom-vido-n70s-android-4-4-2-kitkat-custom-root-firmware-20140517/ with the FZ kernel and now rotation works perfectly. Camera still don't working but that is not really really important to me. Thanks a lot.