Search in the TECH forum for 622 temps.
Add a fan or 2. Solves the heat issues.
I put my 622 on top of 4 spray can lids to get 2 in clearance under the box. One fan on the left side air flow OUT. Held with two side stick on tape
One fan under box flow across the bottom.
Both powered with 9vdc power cube. Fans run slow and quit.
Diagnostic shows avg temp at 97
I might try a laptop USB powered cooler under the box. Many do that
Actually what you hear is normal sound when box is rebooting after updates. If loud sound continues while you watch TV, it is running too hot. I had problem with 612 when sound was so loud I could not watch tv. I replaced fan with generic computer CPU fan. It fixed problem (It is my box not leased). Also, do not place your box inside rack tower or similar place where air cannot circulate freely.