Air constantly shutting down. High temperature in Processor.

Hi,

I've a MacBook Air Mid-2011, 4GB RAM, 256GB SSD (Not the original) and in the last year or so, it's been suffering from "random shut downs".

What I try is the following:

- I identify that the Processor gets very hot so I replace the thermal paste (blue circle in the image above).

- I tried removing the SSD and run the OS in a external disk.

The problem keeps happening.

The processor gets really hot so I suppose that is the reason that the computer is shutting down, right?

Beside changing the logic board, any ideas?

Thanks.

(Sorry, english is not my native language).