Rooting would invalidate the warranty.
Easy rooting U4 / U4Quad
Get ROOT_via_MENU_update_only_HMD.zip HERE
1. Download ROOT_via_MENU_update_only_HMD.zip.
2. Rename the file to "update.zip".
3. Follow standard menu update process for U4.
4. U4 will automatically restart.
5. Enjoy. SUPERUSER installed after reboot :)
:fist bump: