Any file under 500MB (full firmware is ~1.6GB compressed). Any file named “YT3-X90F_UPDATE.exe” – legitimate firmware is always .7z , .zip , or .tgz .
The device will automatically check for available updates. If one is found, tap . lenovo yt3-x90f firmware update
Safe, signed by Lenovo, preserves warranty (irrelevant now), no bootloader unlocking required. Cons: Windows-only, sometimes slow, requires a Lenovo account. Any file under 500MB (full firmware is ~1
Here’s the most direct piece of information for you: tap . Safe