MPB Randomly turns off, and the only sign of life is very quiet fan.

So i've been experiencing a problem with my Macbook Pro recently.

A few months ago it randomly turned off while i was using it with more than enough battery life.

I tried holding the power button but no luck.

Tried charging it but no luck.

The only sign of life was if i put my ear right against the bottom of the screen i could hear what sounded like a sweeping sound generated by the fan. wshhhh whhhh whhh like this.

After being on charge for a while, it would come on with the fan blaring extremely loudly, and as soon as i unplugged the charger it would shut off.

This problem ended about 3 days later after leaving it back on charge, it just came back on as usual as if nothing happenned.

I took it to the Apple Store, and they cleaned the inside to help with the fan issue and performed a software reset.

About a week later the same thing happened, it shut off randomly, this time it didn't come on until the following morning.

This has happened 3 times now, and the laptop is currently back to the Apple Store, and as it's out of warranty there's nothing they can do.

Any ideas?

Background information, i'm no stranger to repairing macbooks and iPhones so if it's something somewhat basic i could probably manage it myself.

Any suggestions would be GREATLY appreciated.

Thank you.

Jacob