Lenovo a390 hangs at the boot logo My Lenovo a390 freezes when I open it. It stops on the Logo 'Lenovo: for those who do.' I removed the battery but it is still hanging on that part. What should I do?
You can try doing the soft or hard reset. Soft Reset is to delete the cache and temporary files that causes your website to get stuck in Lenovo logo. It can be done when phone is at On position, press and hold the Power button for several second, then LENOVO A390 will show the pop-up menu to give option for Reboot the phone. Choose restart/reboot than the LENOVO A390 will do the soft reset or restart.

For hard reset, makes sure that the battery is fully charged. Turn off LENOVO A390 > Press together : POWER + VOLUME UP about several second, that the warning will appear at the LENOVO A390 > Choose: Reset Device or Wipe data or Clear eMMC. 
Also, keep in mind that hard reset will result to complete deletion of your applications and data.