Lenovo A6000 isn't turning on
Try to press the Power button for 30 seconds. Also try to start in fastboot mode (usually volume up or volume down + power button) while being plugged to a computer.

Also, maybe worth a try but will delete user data:


Switch off the device
Press &amp; hold Power and Volume up until screen changes to recovery mode. 
Select Recovery mode. 
Using Volume up &amp; down for navigation. Select Wipe Data/Factory Reset and enter it through Power key.
Now, Select Yes (delete all user data)