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Alternative way to perform factory reset

K

kid0

Lurker
My friend's daughter was playing with the unlocking screen and of course she used up all the attempts and locked the device for good. Since this tablet was bought some time ago just for her amusement, no one remembers what was the google account they used - possibly a phony one created just for the purpose of using the device. This discards google recovery as an option.

It's a cheapo tablet sold here by Walmart under ONN brand. I did some research and have found it's being made by YiFang Digital and marketed as M7000NBD

yifangdigital.com/product/M7000NBD.aspx

According to the manufacturer, it's powered by AML8726-MXS Dual Core + Mali TM-400 and it's running Android 4.2. Unless it came like that from the factory, it's not rooted, and it has only 3 buttons: PWR, VOL UP, VOL DOWN.


My friend doesn't care about the data stored on this device and I offered to help thinking that I will be able to perform a factory reset the usual way. I was wrong.

When I use the PWR + VOL UP key combination, to enter Android system recovery, first thing that shows up after the boot is an Android figure with a red triangle and an exclamation mark. If I press the PWR+VOL UP again, the system recovery menu shows up but I can not navigate through its options. At least not using the VOL UP/DOWN buttons.

The only button that works is the PWR, but since "reboot system now" is the option selected by default, it's the only action I can perform from within this menu.




When the above failed, I thought about ADB as an alternative way. Unfortunately the USB debugging seems to be turned off so, as far as my limited knowledge goes, there is no way of running ADB shell in that case. For obvious reasons, there is also no way of switching it on.



Is there any other option to factory reset this device? Or maybe there is a way to make the system recovery menu respond?

If it makes any difference, I have a Windows 7 desktop and two notebooks running Windows 8 and Ubuntu 13.10 respectively.

Thanks in advance for every suggestion.
 
When you're in the bootloader (if you can) you could try doing it via fastboot. Just plug it into your PC when its in the bootloader. Since there is such little amount of documentation, can't really tell you how.

Run the command "fastboot devices" to make sure its properly detected. Then issue the command "fastboot -w" which wipes the userdata partition and cache. Should reset it back to factory. In theory at least.
 
Thank you for the welcome and your answers.

During the day I did some more tries, but no dice.

ADB is obviously disabled in recovery. When I connect the device it starts charging but Windows Device Manager won't notice any change. "Adb devices" returns nothing and "adb shell" returns "error: "device not found"

I've checked in Ubuntu and it's the same story. Nothing shows up in lsusb while in system recovery menu and I get 2207:0000 ID when on Android's "too many attempts" screen. I can access the tablet as a storage unit (with no acces to root dir of course) but because the debugging is off, even after editing the adb_usb.ini and 51-android.rules I get nothing in "adb devices" .

I tried the bootloader/fastboot approach, as suggested by Demache, but with no luck either. My fingers hurt from trying different key combinations and I accomplished nothing. Even tried the VOL +/- >> connect USB >> press PWR several times procedure, I remember from the original Ainol Novo 7 :)

Indeed there is no documentation for this bloody thing, I imagine it's being sold under many brands and not meant for servicing of any kind.
 
Hi I am new in this forum and viewed your post today.

If you still have the problem you can try using an external keyboard on usb OTG port to navigate on recovery menu.
Also if you have some electronic skill you can check ttl console port (4pins near cpu) with a GSM cable (USB2TTL 3v3) , interrupt normal boot and use uboot HUSH cmd parser to clean userdata and cache partitions.

Let me know if I still can help you.
 
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