Lenovo locked the bootloader on the YT3-850F. To unlock it, you must use the (often found via OEM unlock in Developer Options). Without this, you cannot flash TWRP.
The Lenovo Yoga Tab 3 8.0 (YT3-850F) is a classic tablet beloved for its unique rotating camera and kickstand design. However, with its original software stuck on Android 5.1 or 6.0, many users find it sluggish and outdated for modern apps. Installing a can breathe new life into this hardware, providing updated security patches and a cleaner, faster interface. Current State of Custom ROMs for YT3-850F (2026)
You cannot install a custom ROM like a regular app. You need specific tools. If you skip this section, you will brick your tablet.
Perform a "Factory Reset" wipe in TWRP (Dalvik, Cache, System, and Data). Flash ROM: Select your custom ROM zip and swipe to confirm. yt3-850f custom rom
First boot takes 5-10 minutes . Do not hard reset. You will see the LineageOS boot animation.
If you still want to proceed, search XDA for: "[ROM][UNOFFICIAL][6.0.1] LineageOS 13.0 for Lenovo Yoga Tab 3 8 (YT3-850F)"
Since it's an older device, standard GSI (Generic System Image) installation is difficult unless you have a Treble-compatible base, though some users attempt Android 10/11 GSIs with mixed results. 2. Essential Tools for Lenovo locked the bootloader on the YT3-850F
Access Developer Options on your tablet and enable "OEM Unlocking".
Recent efforts on XDA Forums focus on "cooking" lightweight ROMs that remove Google services to improve performance on its limited 1GB of RAM.
Essential for any flashing. You can find unofficial builds that allow you to back up your existing system. Stock Firmware: The Lenovo Yoga Tab 3 8
Have you bricked your YT3-850F? Visit the XDA Developers forum (Lenovo Yoga Tab 3 8.0 section) for unbricking guides using xFSTK. If you successfully flashed a custom ROM, share your battery life report below.
Lenovo’s Yoga Tab 3 series was revolutionary for its time. The YT3-850F, with its iconic cylindrical hinge, built-in kickstand, and impressive battery life, carved a niche for media consumption. However, like many devices from the 2015–2016 era, Lenovo abandoned software support years ago.