Fix Bootlooped Coby 7033 Tablets

[vampirefo.]

Download
7033_fix



extract and place dual_recovery.img, unsecure_boot.img, boot.img, utscript, 7033_system.tgz on your sdcard.insert the sdcard into your coby 7033 tablet turn the tablet off by using a paper clip or some other small device to insert in hole on back of tablet press and release for 3 seconds.

now press and hold volume up + power until you see Vampirefo top left of tablet, at this point lay tablet down, once tablet is done it will boot into my modified recovery.

Once in recovery mode it's, time to start adb commands.


adb shell

cw_recovery.sh
-----------------------------------------------------
now in recovery scroll down til you see

mounts and storage

select

mount /sdcard

select

press back button

__________________

now continue with adb commands

flash_image kernel /sdcard/unsecure_boot.img

flash_image RKer /sdcard/dual_recovery.img

format_cache.sh

format_data.sh

format_system.sh

busybox tar -xzvf /sdcard/7033_system.tgz

after it finishes

in recovery select

reboot system now

select

no

This video just shows tablet rebooting into recovery mode using latest utscript.

Yes my wife and grandson are talking about something during video oh well, I am trying to replace their conversation with music.

 

[alexzamp]

A very good job, well done. My Akai doesn't reboot; on the screen I have "Finished. Rebooting now" and nothing happens. Any clue?

 

[Traveller]

Likely your device doesn't recognize the reboot command. Either that or the reboot command in the fix is slightly different from the reboot command your device expects.

 

[alexzamp]

Likely your device doesn't recognize the reboot command. Either that or the reboot command in the fix is slightly different from the reboot command your device expects.

Do you think there is something I can do or try?

 

[vampirefo.]

A very good job, well done. My Akai doesn't reboot; on the screen I have "Finished. Rebooting now" and nothing happens. Any clue?

Your tablet's differences from the USA Coby 7033 might be the cause, anyway you can try to use a small micro sdcard, I use 2GB when I flash stuff as all tablets understand small micro sdcards. format the card as fat32 and extract all the stuff directly to the micro sdcard. also keep charger and usb cable plugged into outlet and pc.

other than that, you can try rebooting the tablet by using a paper clip, hold for 5 seconds then press power.

This is based off of below kernel size, if your kernel is in another location or different size this wont work for you.
no other vc882 out there uses the same location for kernel storage that coby uses.

uid=0 gid=0@android:/ # cat /proc/mtd
dev:    size   erasesize  name
mtd0: 00a00000 00100000 "SysInfo"
mtd1: 00b00000 00100000 "Uboot"
mtd2: 07600000 00100000 "kernel"
mtd3: 02c00000 00100000 "RKer"
mtd4: 18000000 00100000 "System"
mtd5: 68000000 00100000 "Data"
mtd6: 20000000 00100000 "Cache"
mtd7: 54800000 00100000 "user"
uid=0 gid=0@android:/ #

 

[alexzamp]

Your tablet's differences from the USA Coby 7033 might be the cause, anyway you can try to use a small micro sdcard, I use 2GB when I flash stuff as all tablets understand small micro sdcards. format the card as fat32 and extract all the stuff directly to the micro sdcard. also keep charger and usb cable plugged into outlet and pc.

other than that, you can try rebooting the tablet by using a paper clip, hold for 5 seconds then press power.

This is based off of below kernel size, if your kernel is in another location or different size this wont work for you.
no other vc882 out there uses the same location for kernel storage that coby uses.

uid=0 gid=0@android:/ # cat /proc/mtd
dev:    size   erasesize  name
mtd0: 00a00000 00100000 "SysInfo"
mtd1: 00b00000 00100000 "Uboot"
mtd2: 07600000 00100000 "kernel"
mtd3: 02c00000 00100000 "RKer"
mtd4: 18000000 00100000 "System"
mtd5: 68000000 00100000 "Data"
mtd6: 20000000 00100000 "Cache"
mtd7: 54800000 00100000 "user"
uid=0 gid=0@android:/ #

Done everything exactly like this, but no result. I thought a clone was a complete clone, I mean an exact copy of the original tablet with no differences at all. So I think I should find a working akai tablet like mine, make a dump image of it, search for the differences with USA Coby mid-7033 and then make all the adjustments to the files you provided, right?

 

[vampirefo.]

Also right atfer boot up

adb shell

dmesg > /sdcard/dmesg.txt

then upload the dmesg.txt as well as a dump from the Akai MID7033 if possible.

I believe my method would work on any vc882 provided the adjustments were made to target the kernel for the device, I would like to have a Coby 7035 USA version to test, my guess my method would work as is, but still I would want to see dmesg.txt and cat /proc/mtd output to verify kernel size and location.

I can target any partition, kernel, cache, system, recovery, data and so on but kernel is the best. What I do is target kernel partition wipe it, install my modified recovery, then trip the bootloader, so it boots normal but in fact it boots my recovery instead of default boot.img. once in recovery we can pretty much fix anything, then flash a good boot.img, replace system, wipe complete tablet, replace bootloader, reboot and so on.

 

[alexzamp]

Also right atfer boot up

adb shell

dmesg > /sdcard/dmesg.txt

then upload the dmesg.txt as well as a dump from the Akai MID7033 if possible.

I believe my method would work on any vc882 provided the adjustments were made to target the kernel for the device, I would like to have a Coby 7035 USA version to test, my guess my method would work as is, but still I would want to see dmesg.txt and cat /proc/mtd output to verify kernel size and location.

I can target any partition, kernel, cache, system, recovery, data and so on but kernel is the best. What I do is target kernel partition wipe it, install my modified recovery, then trip the bootloader, so it boots normal but in fact it boots my recovery instead of default boot.img. once in recovery we can pretty much fix anything, then flash a good boot.img, replace system, wipe complete tablet, replace bootloader, reboot and so on.

Ok, I already started searching for the tablet to make the dump. As soon as I will have any news, I will post it. Thank you and Happy New Year all.

 

[Slider2732]

Great development

Unfortunately though, after my initial jaw drop joy at seeing the top left info appear, i'm in the same position as Alex !
It hangs at the reboot stage.
This is a genuine Coby 7033, so Alex's will perhaps work when mine does.
As far as what i'm using on the PC end...Xubuntu 13.10, adb installed, runs but says 'device not found'. I trust that will change when the shell comes up.
The SDcard is an 8GB, the 2GB that I have is corrupted and basically unusable. This 8GB seems fine, with the boot.img part displaying up to the reboot.

View attachment 12115

 

[vampirefo.]

Here utscriptgood

download this file rename to utscript it is to replace the first utscript.

let the tablet set for a bit as it can take several minutes before it boots into recovery mode.

I have the charger plugged in as well as usb plugged into my computer.

it may takes 2 to 3 minutes before it reboots into recovery, just lay the tablet down and let it set, it will in time reboot into recovery mode.

 

[vampirefo.]

Added video to first post showing the tablet booting into recovery mode using the latest utscript, download it from above post and use it instead of first utscript I posted, must be renamed from utscriptgood to utscript then place it with the other files on sdcard, volume up + power.

 

[Slider2732]

I left the new boot loader running for a clear 10 minutes, but no reboot happened.
Seems odd, saying that all else works to that point.
Here's how it looks though, just for verification of output.

 

[vampirefo.]

Its working as it should, apparently Coby made more than one version of 7033.

The version I have was made ro.build.date=Tue May 22 14:51:09 CST 2012. So we need either earlier or later dumps, Do you know the date on your build.prop?

 

[alexzamp]

I'm still searching for the dump, I tried with the new utscript, sadly no result. It seems me and Slider we have to wait a little more.

 

[vampirefo.]

There are many similar software out, all I can recommend is to try their boot.img and recovery.img with the utscript, remove the other files from sdcard and only use utscript and other vc882 tablet's boot.img, and recovery.img, the recovery.img would need to be renamed boot.img.

Once you find either a real boot.img or a renamed recovery.img to boot via utscript don't do anything else, upload it so we can modify it and add adb.