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ClockworkMod (CWM) Recovery easy install for RK3066 and RK3188 -- TWRP/CWM Flash-Tool and root for RK3288
Please donate to support OMA and CrewRKTablets firmware work, thank you !




2016/04/01

The Playtab HD from Kempler & Strauss is a rk312x device (3126, actually) Quad Core with 1 GB RAM / 8 GB storage and a 9 inches HD display with 1024x600 pixel resolution. It is a tablet fr kids, really, bought it for reading academic files actually, and it was working well, except for the PPI resolution.
Anyway, I flashed Oma's Kempler&Strauss ROM and everything was fine (great ROM for the K&S Playtab!). After some days I mistakenly flashed kernel, uboot, and resources images from the Chuwi V17 HD and everything went bad, tablet would boot to Android and reboot immediately. Somehow (I really do not know how, but it was after I thought it became a complete brick, in the morning, maybe with an actually drained battery) I managed to flash back Kempler&Strauss' the whole ROM again except uboot.img (or at least the download went to 100% in RK Android Tool. Right now I am on a bootloop: Android loads and immediately shuts down because it can't detect battery charge, this gives some brief use of adb, but I can't manage to boot into recovery thru ADB nor keys combination and I really do not know what other key combination can I try.
For those thinking about a firmware update/restore using RK Batch Tool, I have tried v1.7 and 1.8 using the original firmware provided directly from Kempler & Strauss (I have tried two downloads in case of file corruption). The thing is, while RK Batch Tool detects the device (always before it shuts down because of battery "drainage") I can't use the "Switch" button and squares won't turn green. For those thinking I should use my DC charger in addition to my USB cable... well, it remains the same problem, no matter how much time I put the tablet to charge. I disassembled the tablet (it does not have warranty seals) and looked for a "fastboot button" but there is only this reset button.
I know this is a long shot, but I have found really good information in this forum and I thought it was better to try to get help than watching the tablet laying there with no use.
Possible ways to help me:
- Maybe there is a way to fool Android to think I have a completely charged battery
- Maybe a weird combination of keys
- Maybe stop the boot process in some level (like init system in Linux)
- You could explain to me what is uboot.img and why is it ruining this thing. Actually, even if I flashed back Oma's ROM, the problem seems to be the same, I suspect I did not flash anything, but RK Android Tool confirmed the download.
- Whatever you can think of, I am dual booting Windows and Linux, so any suggestions will be welcome. Thanks in advance.


Moderator

Firmware Guru
2012/10/06

Uboot.img contains a stage of the loader. It sounds the loader or the NAND itself has been corrupted somehow.
You need to open the tab to start the first stage bootloader (Mask-Rom), which is loacted in the SoC. In principle like here:
- Oma -
The following users say thank you to Oma7144 for this useful post:
BIOLYASSERPer aspera ad astra, we rock the Tablets !
If you like our firmwares, please consider making a donation to support our work.
Thank you!

2016/04/01

Somehow I knew you would answer. Thank you.
Yesterday I managed to open the tablet and start it in Mask-ROM mode. To be accurate, it took a lot of time to do so, because of the size of the pins, but I made it. So I was ready to flash the firmware with the blue square in the Batch tool, I was really happy to see something different than the pink square. Anyway, the flashing didn't take. The Batch Tool sends an error "Boot Download fail!" or maybe "Download boot failed!". Also I can't erase ID blocks, it's like the NAND chip is not writable at all, so, right now I wiped the system, when connected, the tablet is detected but can't switch to recovery mode (no green square in RK batch tool), I get a stable adb shell though, but there is no OS installed in the filesystem.
Any ideas?


Moderator

Firmware Guru
2012/10/06

There is nothing to do anymore. The NAND chip is gone. Sorry.
- Oma -
The following users say thank you to Oma7144 for this useful post:
BIOLYASSERPer aspera ad astra, we rock the Tablets !
If you like our firmwares, please consider making a donation to support our work.
Thank you!

2016/04/01

Thanks Oma. I managed to get a physical replacement, I know it is not a better tablet (512 RAM, 2 cores and less NAND memory) but somehow I am happy with it. I want to use this tablet (and the first, the messed one) basically for reading documents and the screen looks better (brightier and touch is way more responsive). The battery is another advantage, is a 4000 mAh one, and it becomes less hot, great for my sweaty hands. Anyway, this one is distributed as the Gamer Touch by Digital Guru, I opened it since they do not use warranty seals and found a Rockchip 3026 inside. I was looking for the mobo serial number or chipset number and found nothing so I don't have a firmware to flash in case of messing up things. The other thing is I can't use fastboot to flash img files into partitions by name, I am guessing I need Android RK Tool to flash this backups, but then again, how do I know where to flash those img files?
I already backed up this firmware with your tools. I made a nandroid backup (via onandroid), but I can't find a CWM image for it. First, should I open a new thread for this? Second, is it of any help to have a copy for these backups online with some photos of the insides?
Thank you in advance.


Moderator

Firmware Guru
2012/10/06

Just upload the dumped images and logs to a filehoster. I will check.
- Oma -
Per aspera ad astra, we rock the Tablets !
If you like our firmwares, please consider making a donation to support our work.
Thank you!

2016/04/01

Sure, man. This is the dump ROM at MEGA. I did not upload my nandroid backup because it was not the original recovery (I installed your CWM for rk3066, it boots, but won't read partitions correctly) and my system apps were updated already when I made it.
The dump:

2016/04/01

EDIT: I have been playing around with this so-called GAMERTAB by Digital Guru or Kempler & Strauss or whatever. I have recovered of some problems, but I am unable to have a safety valve without the required firware or with a recoverable system, boot and kernel partitions. Thank you very much, but I will stop with this, my tablet behaves well now. So long...


Moderator

Firmware Guru
2012/10/06

Ok, this is a RK3026 architecture:
ro.build.display.id=rk3026-eng 4.2.2 JDQ39 eng.wangjunxu.20140805.180733 release-keys
ro.product.model=GAMERTAB
ro.product.brand=rockchip
ro.product.name=rk3026
With a simple RTL8188 wifi chip:
<4>[ 39.700302] Current WiFi chip is RTL8188EU.
Dump is ok.
- Oma -
The following users say thank you to Oma7144 for this useful post:
BIOLYASSERPer aspera ad astra, we rock the Tablets !
If you like our firmwares, please consider making a donation to support our work.
Thank you!

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