Two cores of asus zenfone 2 is not working

[Vinay_13]

I have bought asus zenfone 2 laser 5.5, it has octa core processor
But after 5 months when i check on CPU Z app, it shows that from 8 cores ,2 cores are not working.
Showing 0.0
So what is the problem and also give solution for it in steps.

 

[Vinay_13]

MERGED QUESTION
Question from Vinay_13 : "Two cores are not working"

I have bought asus zenfone 2 laser 5.5, it has octa core processor
But after 5 months when i check on CPU Z app, it shows that from 8 cores ,2 cores are not working.
Showing 0.0
So what is the problem and also give solution for it in steps.