My laptop Lenovo ideapad 100 sometimes makes such rattling noises, especially when downloading something what is it?
This is because one of the fans is broken or there's dust in it. To fix this, you would have to unscrew the device and clean the fan.
Can you have it done somewhere and what does it cost
And can anything happen if I don't do that?
Google is between 70-150 euro
But it depends on the provider.