Do you have a pet at home? It’s amazing the amount of hair that can be accumulated in these little spaces. The second one is blocking the device air inlets. There are two ways grime may stop the fans: One is covering the fan itself and clogging the fan. Grime penetrates inside our device through our keyboard or the air inlets of our case. Something so simple, like the continued accumulation of dust, hair, and grease may stop your fans from working.