teclast t20 dead after flashing twrp custom recovery - Android Q&A, Help & Troubleshooting

i downloaded the custom recovery for t20 (TWRP-3.2.3-TwrpBuilder-t20-2019-01-18_20-02) from gethub "i cant attach the link because of the forums rules"
then flashed it using fastboot , but then the tablet didn't boot into normal mode but i was getting the boot mode selection when i hold the (power + volume up) which gave me access to recovery mode and fastboot mode
the problem is that this custom recovery had issues with the touch screen and was basically not usable .
so i switched the phone into fastboot and i flashed the patched boot image that was working before but the tablet still didn't boot into normal mode , then i flashed the stock recovery image and now every thing gone .
the tablet has no options to boot into fastboot or recovery anymore.
basically the tablets boots and i get the teclast logo then the image of the broken android with a "no command" on screen and nothing else
i tried holding the volume up and plug in the usb-c cable but i got the same broken droid
holding volume up and power doesn't give the options for boot modes anymore
i would appreciate any help a this moment , thanks

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hany20006 said:
i would appreciate any help a this moment , thanks
Click to expand...
Click to collapse
SP Flash tool should help you. Install stock firmware and everything should be restored, a device on MTK isn't so easy to kill. Just check the revision of your device (E1 or E2, on the back cover). I tried this TWRP and already spoke of that control it only with mouse (https://forum.xda-developers.com/showpost.php?p=78710093&postcount=5). I have my own version of the TWRP (3.2.2), there's also a problem with orientation of the screen. But PhilZ recovery works without problems, the management of keys.

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ViAlexSt said:
SP Flash tool should help you. Install stock firmware and everything should be restored, a device on MTK isn't so easy to kill. Just check the revision of your device (E1 or E2, on the back cover). I tried this TWRP and already spoke of that control it only with mouse (https://forum.xda-developers.com/showpost.php?p=78710093&postcount=5). I have my own version of the TWRP (3.2.2), there's also a problem with orientation of the screen. But PhilZ recovery works without problems, the management of keys.
Click to expand...
Click to collapse
thanks for the reply my version is E2
i tried flashing the stock but i keep getting an error that the preloader file is not valid . can u upload yours so i can try with it

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hany20006 said:
my version is E2
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Click to collapse
Here's firmware T20 (T2E2)-Android7.1.1_V1.02_8F48 specifically for revision E2: Chinese storage or my Y.Disk
If stock firmware doesn't help you, here's my read preload-partition, I have E2 (I hope you know how to restore it in SP Flash Tool using Write Memory option).
Partition address and size:
Code:
linear_start_addr: 0x0
physical_start_addr: 0x0
partition_size: 0x40000

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ViAlexSt said:
Here's firmware T20 (T2E2)-Android7.1.1_V1.02_8F48 specifically for revision E2:
If stock firmware doesn't help you, here's my read preload-partition, I have E2 (I hope you know how to restore it in SP Flash Tool using Write Memory option).
Partition address and size:
Code:
linear_start_addr: 0x0
physical_start_addr: 0x0
partition_size: 0x40000
Click to expand...
Click to collapse
thank you very much for providing the y.disk link , i spent the whole yesterday searching for a way to download from baidu without luck.
i managed to flash the stock software (using format all +download) and it worked and now the tablet is up and running (unfortunately its chines ) i changed the language but there is bits here and there with chines still i cant complain.
there is no recovery image with this tablet , do u think i should flash the twrp recovery even if it has touch issues.
i cant thank u enough for your help
have a nice day

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hany20006 said:
do u think i should flash the twrp recovery even if it has touch issues
Click to expand...
Click to collapse
See here: https://forum.xda-developers.com/showpost.php?p=78758523&postcount=7

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ViAlexSt said:
See here: https://forum.xda-developers.com/showpost.php?p=78758523&postcount=7
Click to expand...
Click to collapse
yeah i just rooted the device and then flashed the recovery using the Mediatek (MTK) Auto TWRP recovery porter by Team Hovatek (TWRP 3.2.1-0)
the touch screen is till having issues , but i guess i have to use mouse as you said

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Hey guys, have either of you had trouble using the flash tool to flash the patched boot image from Magisk? it will not flash no matter what I do. I just get a red bar .... THanks

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Draiter said:
Hey guys, have either of you had trouble using the flash tool to flash the patched boot image from Magisk? it will not flash no matter what I do. I just get a red bar .... THanks
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Click to collapse
Those are the notes i made for my self regarding your issue:
at the end we may get an error when flashing the patched-boot.img using sp flash tool
so we need to use fastboot instead
first we need to install ADB and fastboot in the PC (follow link bellow):
https://www.howtogeek.com/239798/how-to-unlock-your-android-phones-bootloader-the-official-way/
then power off the device then (hold the volume up+ power ) to enter the BOOT mode (the usb must be disconnected)
then select the fastboot from the menu
then we can use the commands :
#fastboot flash boot c:/patched_boot.img --> make sure the image is in the C folder
if this failed we need to unlock the OEM
#fastboot oem unlock -- > then confirm from the tablet
then try again
#fastboot flash boot C:/patched_boot.img
and when its done we can issue the command for restarting tablet
#fastboot reboot

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hany20006 said:
Those are the notes i made for my self regarding your issue:
at the end we may get an error when flashing the patched-boot.img using sp flash tool
so we need to use fastboot instead
first we need to install ADB and fastboot in the PC (follow link bellow):
https://www.howtogeek.com/239798/how-to-unlock-your-android-phones-bootloader-the-official-way/
then power off the device then (hold the volume up+ power ) to enter the BOOT mode (the usb must be disconnected)
then select the fastboot from the menu
then we can use the commands :
#fastboot flash boot c:/patched_boot.img --> make sure the image is in the C folder
if this failed we need to unlock the OEM
#fastboot oem unlock -- > then confirm from the tablet
then try again
#fastboot flash boot C:/patched_boot.img
and when its done we can issue the command for restarting tablet
#fastboot reboot
Click to expand...
Click to collapse
Hey thanks for the quick reply, I will give it a go
Sent from my SM-G935F using Tapatalk

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Got the boot.img flashed and recovery flashed (Phil's), but cannot do a full backup in recovery, cannot Mount data.
Have you been able to do a full backup?
Sent from my SM-G935F using Tapatalk

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Draiter said:
cannot Mount data
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Click to collapse
Standard phenomenon for Nougat/Oreo: to mount a partition /date, must first format it. With loss of user data!
Some TWRP editions don't require this, /data mounted.

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Hello.
Thanks ViAlexSt for the help, but I´m still having problems with root
, I try with (MTK) Auto TWRP recovery porter and with MTK Auto Philz recovery porter, with success only with TWRP.
Wiith Philz only get into recovery, when go to the OS the screen freeze with Teclast Logo in red.
With TRWP have an error, not able to mound device.
Is no possible install zip or create a backup.
Any idea??
I have a T20 T2E1
Thanks

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I format with SPFlashtool with format+flash option, but not work, no backup, no any wipe.
Still with message Unable to mount parition.
I will try with an older version OF TWRP.
Some screenshots.
Thanks
https://photos.app.goo.gl/qwmLqnhxVk8vRmWA8
https://photos.app.goo.gl/VP5vJCDC7HaDpgaB8

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AWLanzarote said:
Still with message Unable to mount parition.
Click to expand...
Click to collapse
Did you manage to do it? It's necessary to format the partition from CWM/TWRP!
Do you need additional explanations?

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ViAlexSt said:
Did you manage to do it? It's necessary to format the partition from CWM/TWRP!
Do you need additional explanations?
Click to expand...
Click to collapse
Thank you very much for yor reply.
Yes I try formating with twrp but the same problem, at the end I take the risk and use a downloanble image "TWRP-3.2.3-TwrpBuilder-t20-2019-01-18_20-02". The one generated with the porter doesn´t work for my Teclast T20 (T2E1).
With this one "TWRP-3.2.3-TwrpBuilder-t20-2019-01-18_20-02.img works at the first".
And after that I was able to install "Magisk-v18.0.zip" and "no-verity-opt-encrypt-6.0.zip".
And finally I get root access, but after a wile I see the propblem with the IMEI wich was Inavild, after try with many options like generate the file MP0B_001, use Uncletools, droid tools, and many other Apps.
Finally today... I found a solution in a Spanisf Forum Dual Sim, Thanks to user "pedrogem" the most easy way to set an IMEI.
https://play.google.com/store/apps/details?id=com.rungetel.ghostphone&showAllReviews=true
Many Thanks..

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AWLanzarote said:
Thank you very much for yor reply.
Yes I try formating with twrp but the same problem, at the end I take the risk and use a downloanble image "TWRP-3.2.3-TwrpBuilder-t20-2019-01-18_20-02". The one generated with the porter doesn´t work for my Teclast T20 (T2E1).
With this one "TWRP-3.2.3-TwrpBuilder-t20-2019-01-18_20-02.img works at the first".
And after that I was able to install "Magisk-v18.0.zip" and "no-verity-opt-encrypt-6.0.zip".
And finally I get root access, but after a wile I see the propblem with the IMEI wich was Inavild, after try with many options like generate the file MP0B_001, use Uncletools, droid tools, and many other Apps.
Finally today... I found a solution in a Spanisf Forum Dual Sim, Thanks to user "pedrogem" the most easy way to set an IMEI.
https://play.google.com/store/apps/details?id=com.rungetel.ghostphone&showAllReviews=true
Many Thanks..
Click to expand...
Click to collapse
Are you able to make a T20 root step by step guide with all the necessary download's (patched boot.img included) ?
would be very appreciate.
regards

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toxstoxs said:
Are you able to make a T20 root step by step guide with all the necessary download's (patched boot.img included) ?
would be very appreciate.
regards
Click to expand...
Click to collapse
Hi toxstoxs.
Is already done in this link with all the downloads https://romprovider.com/2019/01/teclast-t20-root-twrp/.
I follow these steps exept the use of adb. In stead, I used SP Flash Tool, the utility included in the the original ROM which you can download from the official Teclast website.
Be sure to make the backups mentioned in the procedure NVRAM and nandroid, in case you lose your IMEI you will need restore the NVRAM backup.
With SP flash tools, upload the recovry.img "the downloaded TWRP from the link above" and your boot.img "patched on your device with magisk manager from you original"
I use the boot image from the original rom downloaded from Teclast, which I flash previously.
Be sure to make the backups mentioned in the procedure NVRAM and nandroid, in case you lose your IMEI you will need restore the NVRAM backup.
Just take in mind... touch screeen is not working well in TWRP you should use a mouse, the touch screen is in portrait possition but wou will see the screen in landscape, I do it without a mouse but is not easy, if you can get a mouse will be bether.
Regards.

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AWLanzarote said:
Hi toxstoxs.
Is already done in this link with all the downloads https://romprovider.com/2019/01/teclast-t20-root-twrp/.
I follow these steps exept the use of adb. In stead, I used SP Flash Tool, the utility included in the the original ROM which you can download from the official Teclast website.
Be sure to make the backups mentioned in the procedure NVRAM and nandroid, in case you lose your IMEI you will need restore the NVRAM backup.
With SP flash tools, upload the recovry.img "the downloaded TWRP from the link above" and your boot.img "patched on your device with magisk manager from you original"
I use the boot image from the original rom downloaded from Teclast, which I flash previously.
Be sure to make the backups mentioned in the procedure NVRAM and nandroid, in case you lose your IMEI you will need restore the NVRAM backup.
Just take in mind... touch screeen is not working well in TWRP you should use a mouse, the touch screen is in portrait possition but wou will see the screen in landscape, I do it without a mouse but is not easy, if you can get a mouse will be bether.
Regards.
Click to expand...
Click to collapse
I went troght that step by step guide but :
1) into Pre requirement steps, i made a NVRAM backup with SP Tool.
step 2 is not so interesting to me as the tablet is new so no personal data are saved.
point 3 : How suppose to make a nandroid backup if no TWRP is intalled???
then.. i suppose that it mean to INSTALL a TWRP and just after make a nandroid backup right?
but...
just after ulock the bootloader and reaching step by step the point 7 and 8 of the guide,
after the command "fastboot boot recovery.img" the device reboot and go in permanent loop.
No way to access the recovery.
is there something that i may check? just once i been able to enter the twrp and the main problem were the impossibilty to access and format the /data partition so, no factory reset were possible and obviously no bbot as well (permanent boot loop).

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Im not use adb tools, im only use sp fash tool.
I do it like this.
1 flash the downloaded Rom from Teclast with SP flash tool, to get all fresh.
2 Enable usb debug and oem unlock
3 copy in your device the stock boot.img from the folder firmware from the zip downloaded from Teclast,
4 in your device install the app Majisk manager and use it to patch your original boot.img
5 copy into sd the files magisk.zip, No verity opt encrypt.zip,
6 with sp flash tool flash the patched boot.img and the downloaded TWRP-3.2.3-TwrpBuilder-2019-01-18_20-02"]twrp renamed to recovery.img ”this was the only one trwp which works on my T20”https://github.com/TwrpBuilderTests/android_device_teclast_t20/releases/tag/TWRP-3.2.3-TwrpBuilder-2019-01-18_20-02
7 reboot in recovery with TWRP and install magisk.zip and no verity opt encrypt.zip