I have the manual for my unit, I was merely trying to confirm whether or not I needed to actually remove the unit from being attached underneath the overhead cabinet in order to change this charcoal filter, just seemed accessive to me to have to go to all of that trouble. I see the pic referring to the installation in the manual, and they're showing that the screws to loosen the front grille are on top of the unit, but with the way the unit was installed the screws are inaccessible due to the cabinet top is covering them up. I did loosen 2 of the 3 screws securing the microwave to the cabinet, they are very short threaded screws, barely recessed into the top of the unit. But there is also a third screw that appears to be a longer threaded screw do most of the work securing the microwave. So I was wondering if my assumption is correct and that if the third is a long threaded screw will it allow me to back this screw out far enough to drop the microwave (w/o the unit coming completely off of the cabinet its secured too) in order to access the grille screws. That's what I'm wondering, and the manual really doesn't confirm that. Actually when I got into looking at the grille area, I see that there never was a charcoal filter ever installed into the unit by the installers. Help if you can.
thx

I just assumed it was always un-vented, and just released air out the front through the grille. There is no vent pipe going up through the inside of my cabinet, the wall that the cabinet is attached to is an outside wall to the inside of the garage, so not sure how they would vent it, unless they went through the wall and up through the attic, which I doubt. Actually the retailer I bought this appliance from didn't even install it, my electricians (who were also semi-friends) of mine actually did the install, so I highly doubt that they did some complicated install on this unit. I can only figure that they installed the unit and then saw that the filter needed to be in the grille and weren't about to uninstall the thing to get this small filter in place, but they never passed on any update/info on to me so I was unaware. Heck, I didn't even know it needed a filter, (except the grease filter I've cleaned underneath). So I think I'll just have someone in place to hold the unit in case it comes disconnected from the cabinet when I unscrew the screw, hopefully I can drop the unit down far enough to get a filter in there.

Will do, thx.