Question Fan suddenly goes maximum speed on Samsung Chronos 7

May 30, 2020
After many years of hard work my Samsung laptop shows this problem.
All of a sudden, fan goes maximum speed, apparently with no reason: it's not the classic noise when CPU/GPU are heating and fan raises speed. It sounds full speed like an helicopter lifting off: I had never heard it. And it doesn't stop, even if CPU temperature is low (< 60° C). It only ceases when I turn off PC.
It began to happen when I moved laptop from a table to another, or when I hit (for accident) the table where laptop was on: I thought it was due to vibrations.
Now it happens more frequently, even without any apparent reason.

I replaced thermal paste on CPU, GPU and other chips, but problem keeps showing.

I'm afraid that logic controlling fans went nuts but I don't know how to check it.

Any suggestion?

Thank you in advance,
Jun 8, 2020
What did you replace exactly?
The whole heat sink with the two fans or just a fan?
Where did you buy it?
Thank you!

Replaced just a fan (there is only 1 fan in my laptop)
Fan bought on amazon (look for a fan compatible with your computer; in my case the model of my laptop was listed as compatible with the fan within the description of the object )