You say you continue to hear sound, only the monitor goes black. That should be an indication of a problem related to graphics chip/card. It should not be overheating gfx card issue because your laptop does not freeze. It should be a driver issue.
In certain cases, when the monitor goes black, then the video returns after a few seconds. This is called TDR. In your case, it does not return or you do not wait long enough for its recovery.
What version CCC do you have ? AMD now issues new driver releases for laptops as well except for a few manufacturers, such as Toshiba.
You can try new CCC to see if it resolves the issue.