[Lenovo P11] evolance7:
I had to share my experience with TB-J716F. Dear users, please stay away from ZUI 14.

(ZUI_14.0.127_221020 specifically).

Early this year, my tablet updated from ZUI 13 to ZUI 14. I was pissed, that they removed the PC mode rendering the keyboard accessories useless. After a few days, I got error popping up, UI isn't responding and no more sound coming out the tablet. Going through XDA posts for TB-J716F, it seems that no one had this issue.

Going through a few days of XDA posts, I decided to reflash the firmware to stock ZUI 12 hoping it would revert all the mess Lenovo update had done to my tablet. THIS is when my journey through hell begins.

Had to unlock the bootloader, but Lenovo website that we ask for the unlock file is dead. use the HAHAHAHA method, and managed to unlock after a few days. Tried QFIL to install stock firmware ZUI 12, the tablet stuck in boot loop. I was so heartbroken, I left the tablet in dust for months. I do read the XDA forum for TB-J716F from time to time.

In august 2023, someone posted that ZUI 14.0.266 fixed a lot of problem and PC mode is back. I try again to flash to stock firmware. A ton of sleepless night, I kept failing. I noticed some users said the flashing sometime works and sometime not working, they just keep trying until it works.

Summary of my failure:

1) After flashing with QFIL, the tablet always stuck at bootloop, Even after waiting for hours the welcome page will not load...

2) During bootloop, if I let the screen turn off by itself, I have to restart (hold Power Button) and the tablet will be bootlooping again. Simply clicking power would not wake the screen up.

3) I found a user posted about using the contents_fullupgrade.xml with QFIL. Tried it. still bootlooping.

4) After days of attemps, suddenly the welcome page displayed. I was literally screaming. But after finished the initial setup page, the system message popping up and asking me to restart the tablet, after restart, the tablet stuck in bootloop again.

5) I found out that after flashing the firmware with QFIL using contents_fullupgrade.xml. I have to reflash it again with the original contents.xml. Once I have discovered this, my success rate increase drastically, no more freaking bootloops. The tablet would load the effin welcome page.

6) My heart was broken the second time when I found out that there is still no sound!!!

7) The freaking update destroyed my audio. no more sound via anything (bluetooth, USB dongle), I think the OTA killed the sound chip.

8) Scouring the web, I found this is not the first time Lenovo did this: https://forums.lenovo.com/t5/Lenovo...d-Phablets/Tablet-No-Audio/m-p/4141367?page=2

9) I gradually update the firmware again and now it is on ZUI 14.0.266. STILL NO FREAKING SOUND LENOVO. Glad the PC mode is back.

10) I also noticed a new symptom, that if I turn off the Tablet then turn it back on, sometime it will not boot to Android, it will stuck at the Lenovo icon. I have to force reset (hold power button) and try to turn it on again. it will eventually load ZUI 14.

11) I tries using the Dolby Atmos APK the users shared, but still no sound. I guess Lenovo really bricked the hardware via the software.

12) Fark You Lenovo, you destroyed my tablet.

Thank you very much to XDA users for your shared knowledges. at least I can use my tablet now as a web browser or manga reader. No sound coming out at all thanks to Lenovo. SD870 has a lot of potential, to bad it is crippled with bad software implementation.

DO NOT UPDATE TO ZUI 14 !!!!! STICK WITH ZUI 13!!!!!!!!! You will be a lot happier.