Fix Bootlooped Coby 7033 Tablets

Slider2732

Member
Sep 21, 2013
39
11
Ah ok..making sense. I viewed your video after posting :)
Wonder if they batch dated or day to day dated, i'd hope by batch.
I'm using the dump that Todd posted on the other thread, due to having completely no knowledge of tablets except my wife's PengPod. This tablet was second hand off Ebay and although boxed and great condition the age is unknown.
Serial number is 044120016660
Down the line, when we've worked through etc, serial numbers might be very useful to folks for which build to use ?
The 666 hasn't escaped my attention lol

As a btw, it seems the tablet now doesn't go into the old recovery screen. I guess that means it's actually flashing, but then not seeing the bytes it needs to.

Will try boot.img and recovery.img separately, then together.

Interesting event just now. I mistyped as recovery.omg - let's hope that's a good slip there :)
 
Last edited:

vampirefo.

Senior Member
Developer
Nov 8, 2011
3,836
1,394
when Todd comes back on, hopefully he can post out put of

cat /proc/mtd

adb right after boot up

adb shell

dsmeg > /sdcard/dsmeg.txt

and upload the dsmeg.txt if different size and entry point, I can adjust my utscript to target the new size.

the utscript works perfectly for me cause, I know the exact kernel size, location and the recovery.img and boot.img were both pulled from my device.

this is why backups and other info like dsmeg and cat /proc/mtd are important.

I am hoping Todd's dsmeg.txt is different than mine, so it would hopefully be correct for you guy's tablets.
 
Last edited:

Slider2732

Member
Sep 21, 2013
39
11
Update from here.
I've tried the different files and no luck yet.
The file sizes were markedly different, 33mb for Todd's boot.img instead of 10.7mb (iirc). Different inclusions for different builds probably.
Also, one thing I noted, was that the system.tgz was called 7033_system.tgz in your files vampirefo. I tried renaming that too, just in case.

I have no idea of the way the boot loader works and what language it's written in but - if it's possible to output screen info in a sort of MS-Dos/QBASIC method, call external programs etc, then I wonder about extending that functionality. Say to load jpg's and use a terminally bricked device as a digital picture frame.
 

alexzamp

Member
Dec 22, 2013
16
4
Update from here.
I've tried the different files and no luck yet.
The file sizes were markedly different, 33mb for Todd's boot.img instead of 10.7mb (iirc). Different inclusions for different builds probably.
Also, one thing I noted, was that the system.tgz was called 7033_system.tgz in your files vampirefo. I tried renaming that too, just in case.

I have no idea of the way the boot loader works and what language it's written in but - if it's possible to output screen info in a sort of MS-Dos/QBASIC method, call external programs etc, then I wonder about extending that functionality. Say to load jpg's and use a terminally bricked device as a digital picture frame.

Same here. I think you are on the right path, Vampirefo, so I will try harder to find other dumps.
 

mcclain_ts

Senior Member
Aug 29, 2013
120
42
Per Vampirefo.'s request, here's my "semi-rooted" mid7033 (USB debugging drops with each re-boot) cat /proc/mtd -

cat /proc/mtd
dev: size erasesize name
mtd0: 00a00000 00100000 "SysInfo"
mtd1: 00c00000 00100000 "Uboot"
mtd2: 02000000 00100000 "kernel"
mtd3: 01600000 00100000 "RKer"
mtd4: 18200000 00100000 "System"
mtd5: 68100000 00100000 "Data"
mtd6: 20000000 00100000 "Cache"
mtd7: 5b000000 00100000 "user"
----------------------------------------------
and my lengthy "dmesg > /sdcard/dmseg.txt" can be found on my GoogleDrive here: 7033 dmesg

Hope this helps! I still need to get this fully changed over using Vampire's methods for full root access, and so the USB debugging isn't lost on each shutdown/reboot.(I just haven't had time to use the tablet lately.)
 

mcclain_ts

Senior Member
Aug 29, 2013
120
42
"Most people that come here with a 7035 or 7033 has already broken their tablet, and didn't backup their tablet so we can't help them fix it."

-----------------------------------------------
SO TRUE!(warm smilz) Take just a little time when you get that tablet. Make a dump and have it looked over by a senior forum member. I promise, you won't regret it!(warm smilz)
 

mcclain_ts

Senior Member
Aug 29, 2013
120
42
Wow yours is so different than mine thanks alot. I will work on another utscript.


----------------------------------
It's that BAD huh?? ? I'm sorry to hear that. Makes me wonder, just how many different people Coby had working to create Android systems(different ones for the same model units) for the tablets they were sending to market.
----------------------------------
Thanks Vampire, for ALL your time, energy, and expertise! Hope you're having a great day out there!

-------------
On another note, I don't know HOW you make ANY sense of that "dmesg" ("dmesg > /sdcard/dmseg.txt") text file!(warm smilz) A person really needs to know what they are looking at/what to look for. That much is clear!(smilz)
 
Last edited:

vampirefo.

Senior Member
Developer
Nov 8, 2011
3,836
1,394
----------------------------------
It's that BAD huh?? ? I'm sorry to hear that. Makes me wonder, just how many different people Coby had working to create Android systems(different ones for the same model units) for the tablets they were sending to market.
----------------------------------
Thanks Vampire, for ALL your time, energy, and expertise! Hope you're having a great day out there!

-------------
On another note, I don't know HOW you make ANY sense of that "dmesg" ("dmesg > /sdcard/dmseg.txt") text file!(warm smilz) A person really needs to know what they are looking at/what to look for. That much is clear!(smilz)

I don't use the word WOW often, but these tablet's nands are so different I couldn't think of another word, LOL.

Below is mine, check out the kernel size, and kernel offset, mind blowing.

Linux version 3.0.8-vimicro (timy@urbetter-linux4) (gcc version 4.4.3 (GCC) ) #3 - Pastebin.com

mine

Code:
nand:10m(SysInfo),11m(Uboot),118m(kernel),44m(RKer),384m(System),1664m(Data),512m(Cache),1352m(user)

yours

Code:
nand:10m(SysInfo),12m(Uboot),32m(kernel),22m(RKer),386m(System),1665m(Data),512m(Cache),1456m(user)


mine

Code:
Creating 8 MTD partitions on "mtdparts=vc088x-nand":
0x000000000000-0x000000a00000 : "SysInfo"
0x000000a00000-0x000001500000 : "Uboot"
0x000001500000-0x000008b00000 : "kernel"
0x000008b00000-0x00000b700000 : "RKer"
0x00000b700000-0x000023700000 : "System"
0x000023700000-0x00008b700000 : "Data"
0x00008b700000-0x0000ab700000 : "Cache"
0x0000ab700000-0x0000fff00000 : "user"

yours

Code:
Creating 8 MTD partitions on "mtdparts=vc088x-nand":
0x000000000000-0x000000a00000 : "SysInfo"
0x000000a00000-0x000001600000 : "Uboot"
0x000001600000-0x000003600000 : "kernel"
0x000003600000-0x000004c00000 : "RKer"
0x000004c00000-0x00001ce00000 : "System"
0x00001ce00000-0x000084f00000 : "Data"
0x000084f00000-0x0000a4f00000 : "Cache"
0x0000a4f00000-0x0000fff00000 : "user"

equals 86MB yep 86MB

My kernel space is 118MB yours is 32MB, LMAO that is the biggest difference I have ever see in two a like tablets.
 

mcclain_ts

Senior Member
Aug 29, 2013
120
42
Excuse my expression but,... what the HELL were they thinking/doing?!!! Why would there EVER need to be SUCH a GREAT discrepancy between the two same(okay, but different) units? Just makes NO sense to me, or probably even a 5 year old. If possible, (maybe it's not, but...) find the BEST dump/backup etc., and make the tablet accept it some way or another. I know with the onboard differences, that's NOT always possible. But as long as ALL the hardware's the same, isn't it "do-able"??? ?? ?(smilz)
LOL I agree! Never seen that coming! HUGE difference!LOLLLL I think the key for this fella in Italy, is definitely try and get a dump from an identical and working unit to his. Same hardware, etc. The more people that make those/these dumps, the better off everyone is.
Damn, that's a BIG difference in kernel size! Makes me wonder, what else is different or what other obstacles are there? And WHY are the lesser expensive(but STILL very nice) tablets SO complex?(sighs) My hat's off to you Vampire!

-------------------------------- Pastebin----------
Sure looks much more orderly and easier to read, but still, I can't make sense of it all. That's your "dmseg". When we paste it into that form, it DOES look easier to read at least. I can understand some of it, but definitely not all. I'm still new. Thanks for sharing that with me!(warm smilz) Another great tool!(smilz)
 
Last edited:

alexzamp

Member
Dec 22, 2013
16
4
Excuse my expression but,... what the HELL were they thinking/doing?!!! Why would there EVER need to be SUCH a GREAT discrepancy between the two same(okay, but different) units? Just makes NO sense to me, or probably even a 5 year old. If possible, (maybe it's not, but...) find the BEST dump/backup etc., and make the tablet accept it some way or another. I know with the onboard differences, that's NOT always possible. But as long as ALL the hardware's the same, isn't it "do-able"??? ?? ?(smilz)
LOL I agree! Never seen that coming! HUGE difference!LOLLLL I think the key for this fella in Italy, is definitely try and get a dump from an identical and working unit to his. Same hardware, etc. The more people that make those/these dumps, the better off everyone is.
Damn, that's a BIG difference in kernel size! Makes me wonder, what else is different or what other obstacles are there? And WHY are the lesser expensive(but STILL very nice) tablets SO complex?(sighs) My hat's off to you Vampire!

-------------------------------- Pastebin----------
Sure looks much more orderly and easier to read, but still, I can't make sense of it all. That's your "dmseg". When we paste it into that form, it DOES look easier to read at least. I can understand some of it, but definitely not all. I'm still new. Thanks for sharing that with me!(warm smilz) Another great tool!(smilz)

I totally agree with you, there is no reason for making such differences when the hardware is the same. Copyright problems, may be? All the people in my country with Akai tablets seem vanished, there is no way to find a dump of it. I'll keep searching.
 

mcclain_ts

Senior Member
Aug 29, 2013
120
42
Another thing I've found out about Coby tablets is...

Sometimes the processors inside somehow become mislabeled/mis-tagged etc. I don't know if it's just typo errors by staff placing advertizing ads for the tablets from vendors or what, but for example, some MID9742 claim to have a "Fujitsu" processor inside. But when I physically open them up, I ALWAYS find the standard AllWinner chip, and nothing more. I think sometimes, hired staff for placing resale ads accidentally misname what's actually inside. My honest opinion.
Another thing to think is,...
sometimes other companies will from time to time purchase the rights to reproduce tablets/tablet parts by other names/manufacturers. But I'm almost certain if we all open up our 7033s, and compared them, the hardware is most likely identical. I have found MANY differences in the digitizer/s area however. So if you ever use a different brand digitizer as a replacement for a broken one, make sure you have a way to get the proper driver/s onto the tablet. Vampire just helped me revive a MID7036 with a cracked screen. We used my mom's Nandroid backup from her separate MID7036 unit(same digitizer as the new/replacement) to bring my unit with a cracked DPT brand/model digitizer to 100% functionality.
Thanks again Vampire!
-----------------
Side note - Perhaps you can find a cheap used Akai 7033 on one of the ebay(or other) sites. Another option is to find a replacement logic board and replace it. But I would HIGHLY recommend giving Vampire more time to try to help you out here. It's difficult to repair tablets over the internet, but it can be done. Takes time. I feel for you,... I know the frustration of having a tablet that won't function.
Patience is key/paramount. Hope it all works out!(warm smilz)

---------------
Another side note - If you ever think about buying a used MID9742, try to avoid it if it's mentioned to have a "glitchy" or "dead-spot" digitizer.LOL The manufacturers for A LOT of the 9742 digitizers REALLY made A LOT of bad ones! And the sad thing is, there's no way to interchange parts between them and their counterparts - the MID9740.(my very first tablet - "Thanks MOM!")
 
Last edited:
Top