[Q] RCA RCT6773W22 8GB 7-Inch Touchscreen Tablet - Rooted, but now in bootloop!

[PSCGOhio]

We've managed to get this rooted (see other thread) but now after an adjustment I made, mine's bootlooping.

I did a ton of digging and while there's no apparent ROMs out there, this is a generically made tablet under several brands and makes beyond RCA. RCA and Voyager (RCA Tab parent) claim not to have the ROM for downloading, but that makes no sense for three reasons:

1) How did my tablet know if I had the latest firmware version, etc? It had to surf somewhere and do a check, why can't that also be public or can anyone determine it and we can snag a copy ourselves to distribute?

2) What're they going to do with it if we send it back for 'repair'? I haven't found anyone who has but I'd bet if you tracked the Serial # it'd just be different and they bulk the bricked ones back to China for reloading and resale as 'refurbished'.

3) How exactly did this sucker get MADE? If you had the ROM to load it, hand it built for you, why can't you get it (and back to the updating issue)?

I've discovered this is a Gigabyte based setup, they have a similar model showing but that doesn't mean they made it either - just the hardware states that's what it is. We can't do a ROM that doesn't work on an ARM7 CPU, so the Intel Inside stuff's worthless.

Here's a China declaration about this unit:

We company SHENZHEN ZOWEE TECHNOLOGY CO.,LTD hereby declares:
The product model(s):
DPM7828,DPM7827,DPM7826,TM7005,TM7006,TM7008,NB7856,NB7866 is
identical in the same PCB layout, interior structure and electrical circuits with
the model M7054 which tested in Shenzhen Huatongwei International
Inspection Co., Ltd, the only differences are the model name for commercial
purpose.
The trademarks TMAX, APEX, DOPO, NOBIS, DAGE, NUVISION will be
selected by different customers owing to commercial requirements.

I looked up all those models and brands, again similar stuff but customized for their resale and none have a ROM anywhere that seems to be close!

So any further info you find, tag it onto this thread and if anyone can find a ROM that'd at least get back to access I'd be grateful!

I can ADB, but only sideload.
I can use the microSD, can even push a load to the tab with something on the card but can't find anything.
Have done the wipes, etc. and regardless it keeps rebooting over and over endlessly.

Last change I did was to make Titanium Backup convert to a System file and force it thus I think that's what it's doing and I can't stop it. I'm not that experienced enough with Android (vs. Linux and servers, etc.) to be able to get to and edit some files others have noted that might get me back to normal booting, but without anything but ADB sideloading that may be kinda pointless anyways.

Open to any ideas, thoughts and otherwise! This is a nice, basic tablet with some decent power for the price so if you're hear to just bash stuff or make stupid comments please look elsewhere. Hundreds of us are looking so the solution finder would be a hero!

 

[canodroid15]

Hey guys my daughter got one of these for X-mas, I've not attempted to root it as the kernel date is August 7 2014 and from what I gather any phone or tab with a kernel dated after that can't be rooted yet, I haven't taken any ota's yet either as I've learned my lesson on that in the past, lol! Just wondering if you guys have the same kernel date as mine? I'd love to get xposed on this thing. Thanks in advance, nice to see a dedicated thread for this tab!

 

[Xactot]

Hey guys my daughter got one of these for X-mas, I've not attempted to root it as the kernel date is August 7 2014 and from what I gather any phone or tab with a kernel dated after that can't be rooted yet, I haven't taken any ota's yet either as I've learned my lesson on that in the past, lol! Just wondering if you guys have the same kernel date as mine? I'd love to get xposed on this thing. Thanks in advance, nice to see a dedicated thread for this tab!

My kernel version is Nov 21 2014. Hmm, I wonder if there was an exploit in the older kernel that was patched in the newer version and if so if we could somehow reinstall the older kernel through recovery to re-enable that exploit...

 

[PSCGOhio]

My kernel version is Nov 21 2014. Hmm, I wonder if there was an exploit in the older kernel that was patched in the newer version and if so if we could somehow reinstall the older kernel through recovery to re-enable that exploit...

I can't see my version sadly, but the ID is:
RCT6773-ANDROID4.4.2-6378-V28-V1.7.21

As mentioned I did get it rooted, then did something stupid to get the bootloop. That's all on me, but I rebooted multiple times after root without any incidents, I know exactly how I caused it.

There was some updates elsewhere here from the RCA OTA service, but when I cracked them open they're all for the 6077 model so they'd bomb verification just for not matching! I dont' even know if there's any updates for this one, I never got any when I tried and said it was the most recent. I also tried to change the URL for the OTA and nothing is there for our model.

Whatever we can find seems to have to be something that'll physically change the ROM. I'm looking at the update files from the other models to see if something sticks out we could use to trigger it past this restricted Recovery bootloader. Backups, even my own, keep failing because they need the right MD5 checksum in order to work and it's near impossible to get that especially if you're bootlooped or bricked!

When I try to apply an 'update', mine gets to between the N and the G in installing before it errors out with a problem (not checksum). That's as far as I can get, though from that progress it's getting to a certain point at leasT?

 

[Xactot]

Well, I took the plunge and rooted with iRoot and surprisingly it's not really that bad. I want to switch to SuperSu, so I tried freezing the Super User installed by iRoot, then installing SuperSu, and uninstalling Super User, but that just made me lose root. So I rerooted using iRoot and am stuck with their Super User for now, which is ok I guess. If anyone has specific instructions on how to switch over from the Chinese Super User to SuperSu, please let me know. Thanks.

Anyways, now that I've rooted the tablet and don't seem to have any (immediate) problems or issues,YET, I've made a nandroid backup (both in CWM format and TWRP) of the /boot, /recovery, /system, /data, and /cache folders. I just pulled the CWM and am pulling the TWRP files to my laptop now with adb so once it is done I'll upload it to Google Drive. Here is the link to the main folder which will contain all of my uploads related to this tablet.
https://drive.google.com/folderview?id=0B6Yc110W0bfmSlBMbmh0N2R0VmM&usp=sharing

Maybe we'll be able to deduce something from that information and perhaps solve the MD5 checksum roadblock that PSCGOhio was having among other things.

 

[canodroid15]

My kernel version is Nov 21 2014. Hmm, I wonder if there was an exploit in the older kernel that was patched in the newer version and if so if we could somehow reinstall the older kernel through recovery to re-enable that exploit...

I actually ran into this problem on a Straighttalk s3 (VZW varient) &couldn't root for the 8/7/14 kernel date, I did however get it rooted by Odin flashing the older tar, not sure there's much hope with this tab tho, how ever I've been extracting CM11 apps from my s3 like Apollo, DSP, clock, cm file manager, etc and transferring vie SD card and surprisingly everyone of them installed on the data partition of the tab, pretty sweet!! I still wish I could root this thing tho,

 

[Xactot]

I actually ran into this problem on a Straighttalk s3 (VZW varient) &couldn't root for the 8/7/14 kernel date, I did however get it rooted by Odin flashing the older tar, not sure there's much hope with this tab tho, how ever I've been extracting CM11 apps from my s3 like Apollo, DSP, clock, cm file manager, etc and transferring vie SD card and surprisingly everyone of them installed on the data partition of the tab, pretty sweet!! I still wish I could root this thing tho,

Awesome. I'm glad that worked for you. And you can actually, though I've heard other methods have worked for some, iroot has worked for me. Although I still have to figure out how to swap their Chinese Super User for Super SU lol

 

[canodroid15]

Awesome. I'm glad that worked for you. And you can actually, though I've heard other methods have worked for some, iroot has worked for me. Although I still have to figure out how to swap their Chinese Super User for Super SU lol

You guys have cwm or twrp, for this tab?

---------- Post added at 05:03 AM ---------- Previous post was at 05:00 AM ----------

Awesome. I'm glad that worked for you. And you can actually, though I've heard other methods have worked for some, iroot has worked for me. Although I still have to figure out how to swap their Chinese Super User for Super SU lol

Can't you just install SuperSU from play & let it update the binaries then remove the old su management app that's what I've done on similar devices b4

 

[Xactot]

You guys have cwm or twrp, for this tab?

---------- Post added at 05:03 AM ---------- Previous post was at 05:00 AM ----------



Can't you just install SuperSU from play & let it update the binaries then remove the old su management app that's what I've done on similar devices b4

It's still being worked on although I was reading about different possibilities in another thread
and
If SuperSu actually found the binaries for my tablet, then yes I could. However the update binaries process failed so, I was unable to do so.

 

[canodroid15]

Hey guys need a little help, I managed to root with iroot kinda, the su binary is in xbin & weird superuser apk is in app drawer & can't be uninstalled but I can't get root access, I've tried everything? Not new to rooting at all but new to Chinese lol? any help would be greatly appreciated!! Thanks in advance

 

[PSCGOhio]

Well, I took the plunge and rooted with iRoot and surprisingly it's not really that bad. I want to switch to SuperSu, so I tried freezing the Super User installed by iRoot, then installing SuperSu, and uninstalling Super User, but that just made me lose root. So I rerooted using iRoot and am stuck with their Super User for now, which is ok I guess. If anyone has specific instructions on how to switch over from the Chinese Super User to SuperSu, please let me know. Thanks.

Anyways, now that I've rooted the tablet and don't seem to have any (immediate) problems or issues,YET, I've made a nandroid backup (both in CWM format and TWRP) of the /boot, /recovery, /system, /data, and /cache folders. I just pulled the CWM and am pulling the TWRP files to my laptop now with adb so once it is done I'll upload it to Google Drive. Here is the link to the main folder which will contain all of my uploads related to this tablet.
https://drive.google.com/folderview?id=0B6Yc110W0bfmSlBMbmh0N2R0VmM&usp=sharing

Maybe we'll be able to deduce something from that information and perhaps solve the MD5 checksum roadblock that PSCGOhio was having among other things.

I'll try anything at this point! LOL It's all appreciated. DO NOT, as I've mentioned, turn things into System Apps! That's where I nailed mine with Titanium Backup, that goes way down into the core boot and screw it up ever so slightly for the bootloop. Before that, same as you mine was cranking out just fine.

 

[PSCGOhio]

I'll try anything at this point! LOL It's all appreciated. DO NOT, as I've mentioned, turn things into System Apps! That's where I nailed mine with Titanium Backup, that goes way down into the core boot and screw it up ever so slightly for the bootloop. Before that, same as you mine was cranking out just fine.

Also I didn't get CWM or TWRP in before this happened, so I'm trying to see if I can get either of those converted into a ROM that'll fly. I think I had that Userdata and that's failing the MD5 but as I've read elsewhere that's kind of expected (and annoying). I've tried a couple of alleged fixes for that issue, none have worked.

One issue I have that I may start another thread on, is connecting? I've got the drivers, found the right one and you hear a tone when I plug the USB cable in. But within a couple of seconds it flips over to Charging mode and kills the port! I even moved it down to COM3 to ensure it wasn't looking high and not finding it. The ONLY time it'll start a connection again is if I trip Apply Update via ADB. Obviously then it'll only sideload anyways.

Is anyone getting this sucker to connect and stay that way from the start before the charge cycle kicks in? Every program I've tried for ROMs, flashing and more never sees or communicates with this thing and that could be part of my battle. I've got it set right, even 115200 baud, but no go!

 

[vampirefo]

Well, I took the plunge and rooted with iRoot and surprisingly it's not really that bad. I want to switch to SuperSu, so I tried freezing the Super User installed by iRoot, then installing SuperSu, and uninstalling Super User, but that just made me lose root. So I rerooted using iRoot and am stuck with their Super User for now, which is ok I guess. If anyone has specific instructions on how to switch over from the Chinese Super User to SuperSu, please let me know. Thanks.

Anyways, now that I've rooted the tablet and don't seem to have any (immediate) problems or issues,YET, I've made a nandroid backup (both in CWM format and TWRP) of the /boot, /recovery, /system, /data, and /cache folders. I just pulled the CWM and am pulling the TWRP files to my laptop now with adb so once it is done I'll upload it to Google Drive. Here is the link to the main folder which will contain all of my uploads related to this tablet.
https://drive.google.com/folderview?id=0B6Yc110W0bfmSlBMbmh0N2R0VmM&usp=sharing

Maybe we'll be able to deduce something from that information and perhaps solve the MD5 checksum roadblock that PSCGOhio was having among other things.

Ok, looking at your files, you don't have boot or recovery, your filesystem is ubifs instead of ext4.
ubifs filesystem is prone to bootloops, I will pass on this tablet,
I had been waiting for it to go on sale, to get one, but now I don't want one.

 

[Xactot]

Ok, looking at your files, you don't have boot or recovery, your filesystem is ubifs instead of ext4.
ubifs filesystem is prone to bootloops, I will pass on this tablet,
I had been waiting for it to go on sale, to get one, but now I don't want one.

I meant that those folders were contained within the backup. Sorry for the confusion. It definitely would have been great to have it in that format. I used the "Online Nandroid Backup" app, so that's what I got. My intention wasn't for it to be for backups though, only as a chance to study the system and maybe find out more about the tablet. And ironically, this tablet is being sold on Amazon for $100 on sale. Originally, it was $140.00 lol.

 

[vampirefo]

I meant that those folders were contained within the backup. Sorry for the confusion. It definitely would have been great to have it in that format. I used the "Online Nandroid Backup" app, so that's what I got. My intention wasn't for it to be for backups though, only as a chance to study the system and maybe find out more about the tablet. And ironically, this tablet is being sold on Amazon for $100 on sale. Originally, it was $140.00 lol.

No problem, you might as well pull recovery and boot from that tablet.

adb pull /proc/dumchar_info

now upload dumchar_info and lets see what and where you have.

 

[Xactot]

No problem, you might as well pull recovery and boot from that tablet.

adb pull /proc/dumchar_info

now upload dumchar_info and lets see what and where you have.

Ok definitely will do that in a couple of minutes. I shut the tablet down and lost root, so I have to reroot it again. Figures lol

 

[PSCGOhio]

Ok definitely will do that in a couple of minutes. I shut the tablet down and lost root, so I have to reroot it again. Figures lol

Not sure how we could do that, as I've mentioned continually - we can only adb sideload. The other commands are locked out. Even rooted, unless there's a way to unlock the bootloader to get full adb commands that hasn't been mentioned, I haven't been able to do anything else?

 

[Xactot]

Not sure how we could do that, as I've mentioned continually - we can only adb sideload. The other commands are locked out. Even rooted, unless there's a way to unlock the bootloader to get full adb commands that hasn't been mentioned, I haven't been able to do anything else?

So what exactly is the dumchar_info file anyway? And are you saying that it can't be pulled from the tablet while it is running normally?

 

[vampirefo]

So what exactly is the dumchar_info file anyway? And are you saying that it can't be pulled from the tablet while it is running normally?

It's pulled from normal mode, it is a file that shows all your partitions.

 

[PSCGOhio]

So what exactly is the dumchar_info file anyway? And are you saying that it can't be pulled from the tablet while it is running normally?

It deals with info of the file structure, partitions and such, and you might get at that while it's running. Not sure where it's buried.

But he's saying to ADB pull it, which AFAIK ain't possible in any circumstance on this tablet. If I could've pulled and pushed I'd have this solved by now editing faulty files that caused this bootloop I have. RCA/ALCO had this thing made for them with a lock so that all we can get is Recovery and in there, only the ability to adb sideload something (barely). We can't even Fastboot, it just sits and spins.

 

[Xactot]

It deals with info of the file structure, partitions and such, and you might get at that while it's running. Not sure where it's buried.

But he's saying to ADB pull it, which AFAIK ain't possible in any circumstance on this tablet. If I could've pulled and pushed I'd have this solved by now editing faulty files that caused this bootloop I have. RCA/ALCO had this thing made for them with a lock so that all we can get is Recovery and in there, only the ability to adb sideload something (barely). We can't even Fastboot, it just sits and spins.

??? Ummm, I was ADB pulling files from my tablet last night. That's how I got the backups to my computer to upload to Google Drive. Are you sure it's not just you?