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.