Boox Tab8C got bricked after root attempt

[alonerbg]

I have a Tab 8C (Tab miniC china version), wifi region problem because I live outside china, tried to sideload Tab MiniC firmware and success. But the same wifi problem, then I tried to root to edit wifi region code based on this guide (using QFIL), now my device stuck on Onyx logo, can enter recovery and fastboot mode, here are what I tried to unbrick it but got no success:
1. Use fastboot to fastboot boot boot_a.bin (and boot_b.bin : 2 files backup frim QFIL before root)
2. Extract payload.bin file from update.zip and Use multiple fastboot command to boot.
2. Cannot Wipe date on recovery mode: Unable to merge partitions to complete merge, unable to check merge status... unable to check update status...
3. Cannot sideload update.zip file (both for tab miniC firmware Error Code: kInstallDeviceOpenError and for tab8C update.zip: update package is older than the current build....)
4. Cannot use QFIL, I was able to hold the power button and then the usb regconize as qualcomm hs-usb qdloader 9008 but when I tried tool -> partition manager : switch to EDL failed, download fail: fail to find QDloader port after switch.

On the attachment is my powershell and tab screen when i did the fix

If anyone has a solution I'm very appreciate, this got me so desperate these days.

[dcarvil]

Originally Posted by alonerbg

I have a Tab 8C (Tab miniC china version), wifi region problem because I live outside china, tried to sideload Tab MiniC firmware and success. But the same wifi problem, then I tried to root to edit wifi region code based on this guide (using QFIL), now my device stuck on Onyx logo, can enter recovery and fastboot mode, here are what I tried to unbrick it but got no success:
1. Use fastboot to fastboot boot boot_a.bin (and boot_b.bin : 2 files backup frim QFIL before root)
2. Extract payload.bin file from update.zip and Use multiple fastboot command to boot.

The flash and boot commands have been removed from fastboot, so 1 and 2 above accomplished nothing. I suspect you will have to flash a full factory image to restore the partitions, but I can't tell you how to do that. Renate will likely have some suggestions.

[Renate]

Flashing Chinese to international requires you to bypass some checks.

I've done this before for others but it usually means that I have to make a custom recovery for their device.

[alonerbg]

Originally Posted by Renate

Flashing Chinese to international requires you to bypass some checks.

I've done this before for others but it usually means that I have to make a custom recovery for their device.

Can you try and help me please

[Renate]

Do you have the current TabMiniC update already?
Does it include the recovery? Can you extract it with some paydumper?
Are you willing to work on this on a timely basis because it's going to take some iterations?

[alonerbg]

Originally Posted by Renate

Do you have the current TabMiniC update already?
Does it include the recovery? Can you extract it with some paydumper?
Are you willing to work on this on a timely basis because it's going to take some iterations?

yes I have both update for tab8c and tabmini C upx, and I can extract it and I have time, please help me.

[Renate]

Ok, you have a link. I'm not saying that this is going to work correctly the first time.

Find your current slot or just use both.
Flash rec.img to recovery.

adb reboot recovery
-- should boot to a white screen after Onyx/Boox logo
adb shell
-- got ADB? With a # ?
id
-- does it say "root"
start autoupdate
-- did you get a nice "Waiting for flash"? Legible? Right side up?
-- put update.zip (decrypted) on a flash drive or an SD card and stick in device
-- does it run? To the end? Happily? Did it reboot to your new system?

[alonerbg]

Originally Posted by Renate

Ok, you have a link. I'm not saying that this is going to work correctly the first time.

Find your current slot or just use both.
Flash rec.img to recovery.

adb reboot recovery
-- should boot to a white screen after Onyx/Boox logo
adb shell
-- got ADB? With a # ?
id
-- does it say "root"
start autoupdate
-- did you get a nice "Waiting for flash"? Legible? Right side up?
-- put update.zip (decrypted) on a flash drive or an SD card and stick in device
-- does it run? To the end? Happily? Did it reboot to your new system?

I'm sorry but I'm confused, the tab 8C I own does not have an SD card slot, or do you mean I need to stick a flash drive to the type C hub and connect to the type C port of the tab?

[Renate]

Originally Posted by alonerbg

I'm sorry but I'm confused, the tab 8C I own does not have an SD card slot, or do you mean I need to stick a flash drive to the type C hub and connect to the type C port of the tab?

If you have a Type C flash drive, plug it in.
If you have a Type A flash drive either plug it into a Type C to Type A OTG adapter or plug it into a Type C to Type A hub.
Just plug something in.

But more to the point, did you actually do anything yet?
You're worrying about things that we haven't even gotten to yet.
We don't know that the custom recovery works at all.

[alonerbg]

Originally Posted by Renate

Ok, you have a link. I'm not saying that this is going to work correctly the first time.

Find your current slot or just use both.
Flash rec.img to recovery.

adb reboot recovery
-- should boot to a white screen after Onyx/Boox logo
adb shell
-- got ADB? With a # ?
id
-- does it say "root"
start autoupdate
-- did you get a nice "Waiting for flash"? Legible? Right side up?
-- put update.zip (decrypted) on a flash drive or an SD card and stick in device
-- does it run? To the end? Happily? Did it reboot to your new system?

Thank you, I spent the weekend to work on this, but after some attempts from before, like trying with flash commands and EDL mode using QFIL, the device now cannot be put to recovery mode, the light on the power button is always on, and when I write ./fastboot devices it is still recognized, but when I check with : fastboot reboot fastboot => fastboot: error: Failed to boot into userspace fastboot; one or more components might be unbootable.
I tried to hold the power button method multiple times to put into recovery mode but not working

[Renate]

I have zero idea what you did or what state your device is in.