Please prepare a SD card, and then follow instruction bellow to restore karaoke system. 
STEP 1: Upgrade system:
- 1. Download the updating files from link bellow and lemonktv Apk file.
system updating file:
click here to download Lemonktv_uroot file
lemonktv Apk file:
click here to download lemonktv_player_install.apk - 2. After download, unzip"lemonktv_uboot.rar", you will get five files in it.
factory_update_param.aml
u-boot-aml-ucl.bin
uImage_recovery
update_patch.zip
remote_ir.conf
- 3. Copy above five file and "lemonktv_player_install.apk" (total six file) into your sd card (don’t put them in any subfolder)
- 4. Insert SD card to the SD port of KTV player.
- 5. Power on the karaoke player, select [Android] on launcher interface, [Android]--> [Upgrade]-->[Local Upgrade]->[Update.zip]->[Reboot and Install package]. Wait a moment, the KTV player will automatically reboot.(if your KTV player can't go display any launcher interface,Please turn power off the KTV player, Take off the top cover of player, then press and hold the "reset" button on main board . Please refer image bellow. Please don't release the "reset" button,in the time ,turn the power-switch on. release the "reset" button when the @9 symbol appears .)
(The Upgrade option is at the 2nd page of APPS, click page down button, you will see it, see image bellow) 
- 6. Waiting for a moment (no display at the beginning). When you see a rotating robot, that means the player is updating.
(Warning: Do NOT power off when updating!)
- 7. Upgrade finished, restart automatically, select "com. android provision Default Activity", click "NEXT" button until launcher interface display.
STEP2: Install KTV apk in your system:
- Restart karaoke player, go to [android] --> [Appinstallation]->[/mnt/sdcard]->[LemonKTV] to install lemonktv_player_install.apk .
After installation finished, go to [karaoke]-->press “setup” button, then select [setup KTV]-->[Option]-->[default]-->[reset], click “setup” button to quit the menu, upgrade is finished. Test the machine again. (The "Default" option is at the bottom of the Option menu, you could click "down arrow" button of remote controller to get it.)
