I hope you haven't given up on this as I have the solution to your problem.
Yesterday I had exactly the same problem as you with my tablet. (Zenithink ZT-282 C91 H3 1n)
It is very important that you check you have the same version of the C91 Upgraded tablet. (barcode M3 C91-1n-h3)
But after looking around for info and links I managed to find the right files.
After trying all sorts of different file versions I realized that my best bet would be to flash the tablet back to the factory firmware version. (0316)
Here is the link to the FTP server where I found the files: ftp://zenithink.cn:10021/pub/dyliao/zt-282/
Now, you're going to need a microSD card with at least 1GB for the flash procedure. In the root of the card create a folder and name it "zt-update".
Download the following files and paste them inside "zt-update".
First of all download the boot files that are going to reset the tablet with the autoscript:
Then download this ROM file which will integrate part of the package:
Next, download the firmware files from here:
Then get the kernel from here:
Get the boot screen and update screen from here:
Then download the autoscript which will clean any installed corrupted kernel:
Then download the firmware update from Zenithink website and extract it to your "zt-update" in the microSD.
When you have all these files in the "zt-update" folder in the root of your microSD, you have a working firmware factory reset package.
The procedure I used was the following:
1- eject the card from the computer before disconnecting. This will insure no corruption to the files in the card.
2- with a paper clip reset the tablet and leave it off.
3- insert the microSD card with the files in the "zt-update" into the tablet.
4- turn the tablet on just by pressing the power button. NOTE: press and hold the power button until the system update starts.
it will ask you to press the camera button to confirm the update procedure. Press it as it prompts you to. It should prompt a couple of times.
Once the update starts let it run until the tablet boots up completely and shows you the Setup Wizard.
5- complete the setup wizard and then shutdown your tablet.
6- remove the microSD from the tablet and connect it to your computer. Browse into it and get into the "zt-update" folder and delete the autoscript file.
7- eject the microSD card and remove it from the computer and re-insert it into your tablet.
8- now press and hold the camera button for 5 seconds and while it's pressed, press and hold the power button. while pressing both buttons wait for the message to start flashing the new working firmware and kernel.
Once the flashing process is complete you should run the setup wizard again.
This is the process I used which brought my tablet back to life from a bad Chanante firmware flash.
Let me know how this works for you.
Hope this helps.
thx for that, it also works perfect with the H3_1a Files