Check out how to easily wipe cache partition in BLU Advance 5.2. This operation won't affect your personal files it will only remove temporary cache files. As a result you can refresh Android 7.0 Nougat system and optimize MediaTek MT6580.
Firstly, turn off the mobile by pressing the Power key for a few seconds.
After that hold down Volume Up and Power buttons for a short while.
When the BLU logo appears let go of all keys.
Click Volume Up and Power button when the Android Robot pops up.
Now select "Wipe Cache Partition". Use Volume buttons to scroll down and the Power key once.