You could open with a prop gag. Take a spool of receipt paper up with you stashed in a pocket & say that the management told you there's an SJW convention in town and provided a list of things not to joke about - pull out the receipt paper and "accidentally" have it unspool offstage.
"We've isolated the problem, it appears to be coming from somewhere between your keyboard and the back of your chair."
But I also create stuff using Teradata, Excel, MySQL, Tableau, etc.
As others have said, suspect the fan belt. Check the belt where it would rub against the pulleys - if it's shiny, it needs replacing.
Also, dead critters (or pedestrians) in the grill can impede airflow through the radiator - remove them.