Fix Bootlooped Coby 7033 Tablets

alexzamp

Member
Dec 22, 2013
16
4
Hi guys, Great Success!!!! The tablet rebooted in recovery mode. Right now I'm preparing a machine with linux on it so I can continue the adb part. I sure hope everything will go smoothly. I will keep you posted. vampirefo, on tuesday I will put money on my prepaid credit card and we will share a good coffee (italian, if you don't mind).

While preparing the machine with linux I thinked to the Android SDK. I downloaded it, installed in windows 7 and everything worked perfectly!!!!!!!!

Vampirefo, I confirm the coffee. Slider, thank you for your spiritual support. Thank you all for being so patient with me.
 
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vampirefo.

Senior Member
Developer
Nov 8, 2011
3,836
1,394
Hi guys, Great Success!!!! The tablet rebooted in recovery mode. Right now I'm preparing a machine with linux on it so I can continue the adb part. I sure hope everything will go smoothly. I will keep you posted. vampirefo, on tuesday I will put money on my prepaid credit card and we will share a good coffee (italian, if you don't mind).

While preparing the machine with linux I thinked to the Android SDK. I downloaded it, installed in windows 7 and everything worked perfectly!!!!!!!!

Vampirefo, I confirm the coffee. Slider, thank you for your spiritual support. Thank you all for being so patient with me.

OK, this is great news, all tablets working, couldn't asked for a better outcome.
 

vampirefo.

Senior Member
Developer
Nov 8, 2011
3,836
1,394
At this point we know Coby has made two versions of 7033, (118MB, 32MB) I suspect there is a third version, as Coby has made 3 versions of other tablets. Coby 7035 uses the same recovery as the 7033, and it's possible that there are more than one version of 7035 as well. The Coby 7035 system and boot.img is different than 7033, cause the touch screen is different.
 
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Slider2732

Member
Sep 21, 2013
39
11
I've run the battery down 4 times so far lol, then keep borrowing the wife's charger.
Meant to ask earlier..does the now recovered tablet feature the switch off of that dreaded bootloop counter ?
It scarce matters I guess, if we can now reset, but I just wondered.

Ah Alex, my mum was ordained as a vicar last year at the age of 63...perhaps there's an influence :)
But really, you could be I and we all were affected unknowingly by Coby's weird practices.
A couple of tips for the adb commands perhaps...
Firstly, when entering the Terminal, adb didn't work, but with Ubuntu at least the machine prompted a download to enable. There's no special privileges needed or anything if you set up as single user from a Live CD. It just works :)
Second, just copy and paste the lines, one by one and you'll see it chug through various procedures, each taking a few seconds. Initially the end command where we select 'no' for the 'reboot now' section confused, but it becomes clear when you get to that section. There are a bunch of options down the page that you'll see, all no's with one yes. The yes isn't what's needed to finish.
 
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vampirefo.

Senior Member
Developer
Nov 8, 2011
3,836
1,394
I've run the battery down 4 times so far lol, then keep borrowing the wife's charger.
Meant to ask earlier..does the now recovered tablet feature the switch off of that dreaded bootloop counter ?
It scarce matters I guess, if we can now reset, but I just wondered.

Ah Alex, my mum was ordained as a vicar last year at the age of 63...perhaps there's an influence :)
But really, you could be I and we all were affected unknowingly by Coby's weird practices.
A tip for the adb commands perhaps...just copy and paste the lines, it worked over here. Initially the end command where we select 'no' for the 'reboot now' section confused, but it becomes clear when you get to that section. There are a bunch of options down the page that you'll see, all no's with one yes. The yes isn't what's needed to finish.

It shouldn't, but Coby could have hidden another one I missed, I fixed what I could find, if you flashed the recovery to your tablet, then it will be able to fix the problem if it should happen.

if the problem happens

adb shell

cw_recovery.sh

format_cache.sh

format_data.sh

reboot now

Sad that Coby put so much time and technology into securing this tablet, that they inadvertently created a defective product, the security is so tight that in time their security measures destroys their tablets.
 
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vampirefo.

Senior Member
Developer
Nov 8, 2011
3,836
1,394
@ coby7035

Here is Folken's 7035 dump, I can't verify that it works as I don't have a 7035, you will need the system and boot.img from a 7035 to fix your 7035, the 7033 recovery will work for you.

http://www.androidtablets.net/forum...-coby-generation-3-devices-21.html#post228991

Also read below thread, according to this guy his Coby 7035 is a telechips, which is completely different than VI Micro, which is what this thread is for VI Micro not telechips, seeing my recovery is working on your 7035, it would be a VI Micro.

http://www.androidtablets.net/forum/coby-generation-3/59941-mid7035-cwm-problem.html
 
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alexzamp

Member
Dec 22, 2013
16
4
I've run the battery down 4 times so far lol, then keep borrowing the wife's charger.
Meant to ask earlier..does the now recovered tablet feature the switch off of that dreaded bootloop counter ?
It scarce matters I guess, if we can now reset, but I just wondered.

Ah Alex, my mum was ordained as a vicar last year at the age of 63...perhaps there's an influence :)
But really, you could be I and we all were affected unknowingly by Coby's weird practices.
A couple of tips for the adb commands perhaps...
Firstly, when entering the Terminal, adb didn't work, but with Ubuntu at least the machine prompted a download to enable. There's no special privileges needed or anything if you set up as single user from a Live CD. It just works :)
Second, just copy and paste the lines, one by one and you'll see it chug through various procedures, each taking a few seconds. Initially the end command where we select 'no' for the 'reboot now' section confused, but it becomes clear when you get to that section. There are a bunch of options down the page that you'll see, all no's with one yes. The yes isn't what's needed to finish.

Thank you for your advice, but I did everything in windows installing the android sdk. I'm sure your mother's influence is there:rolleyes:


Vampirefo: At this point, just to be greedy, is it possible to root the tablet and squeeze something else out of it?
 
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coby7035

Member
Jan 3, 2014
9
1
Thanks, I'll look into that after work ; currently unable to involve more hehe
yesterday I tried the cw_recovery.sh it said "file not found" or something. and didnt have time to dig more;...
I'm not even sure adb actually sees the tablet when connected via USB.

thanks, and I'll give you more detail of the result later

btw this is really a coby mid7035, so whatever info/dump you would like from it, I'll give it as soon as I can! Folken provided a dump I see. Well anyway, m,aybe I've got a different version!

bye!

-coby7035
 
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coby7035

Member
Jan 3, 2014
9
1
Thanks, I'll look into that after work ; currently unable to involve more hehe
yesterday I tried the cw_recovery.sh it said "file not found" or something. and didnt have time to dig more;...
I'm not even sure adb actually sees the tablet when connected via USB.

thanks, and I'll give you more detail of the result later

btw this is really a coby mid7035, so whatever info/dump you would like from it, I'll give it as soon as I can! Folken provided a dump I see. Well anyway, m,aybe I've got a different version!

bye!

-coby7035

Hi vampirefo!!
It progressed somehow, realized that the driver for the android usb were not correctly installed.
Now, I could launch cw_recovery.sh and everything else on your list.
all mid7033 settings.
but trhe device didn't want to boot correctly after.
Then I tried with folken's boot.img (over 118 mb size)
It didn't even pass the "fatload boot.img" step, then I realized it may have something to do with utscript ?! do I have to changhe the size in there ?!

By the way thank you so much...!

Edit: I will post post output from

cat /proc/mtd asap.
 
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vampirefo.

Senior Member
Developer
Nov 8, 2011
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folken's boot.img could be bad no way to test it, most likely we need more 7035 dumps.
 

coby7035

Member
Jan 3, 2014
9
1
folken's boot.img could be bad no way to test it, most likely we need more 7035 dumps.

Okay, to take into consideration.
I will be patient on that side, and try more testing with Folken's one.

And like I said, I will output the /proc/mtd when I can.

Thank you and have a nice one!
 

coby7035

Member
Jan 3, 2014
9
1
Here's from /proc/mtd

# cat /proc/mtd
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"


Also... while flashing kernel I noticed that:

mtd: successfully wrote block at 4400000
mtd: not writing bad block at 0x04500000 (ret 1 errno 2)
mtd: not writing bad block at 0x04600000 (ret 1 errno 2)
mtd: successfully wrote block at 4700000

Internal memory has bad sectors ? well actually, that would be the mini sdcard ?

Anyway, no other result from me yet, I had no success, it stills stick at the Coby logo screen after rebooting.

Cheers!
 

vampirefo.

Senior Member
Developer
Nov 8, 2011
3,836
1,394
Here's from /proc/mtd

# cat /proc/mtd
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"


Also... while flashing kernel I noticed that:

mtd: successfully wrote block at 4400000
mtd: not writing bad block at 0x04500000 (ret 1 errno 2)
mtd: not writing bad block at 0x04600000 (ret 1 errno 2)
mtd: successfully wrote block at 4700000

Internal memory has bad sectors ? well actually, that would be the mini sdcard ?

Anyway, no other result from me yet, I had no success, it stills stick at the Coby logo screen after rebooting.

Cheers!

You have exactly same size as my 7033, yours is an 118MB, You are flashing 7035 kernel? 7033 kernel most likely wont boot on a 7035.

the bad block is ok, nothing to worry about.
 

coby7035

Member
Jan 3, 2014
9
1
You have exactly same size as my 7033, yours is an 118MB, You are flashing 7035 kernel? 7033 kernel most likely wont boot on a 7035.

the bad block is ok, nothing to worry about.

Yes, what I did is to use your boot.img for the fatload, then
Folken 7035's boot.img, recovery.img and system in CW Recovery.
and unfortunately the kernel failed to write completely. it stops with an error, let's say, half way...

I'll post the error when I have a chance to reproduce it.

Thanks!
 
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