This forum has expert technicians but the pay is so low that you have to lay out the problem with exactly what you need advice on. Replacing parts the high priced techs do all the time at 100 per hour. Techs here like to repair or fix without replacing if possible.
Non working fan could be a fuse, bad wire connection, faulty switch, burned out motor, too much dust in the bearings, or jammed fan from mud dubber wasps. Or a simple push on the bar that opens the vent.
Descriptions are good but a picture is easier to see.
Do a search using the google dropdown menu.