A drive bay opening in the front bezel portion of a tower type computer CPU unit is provided with a swing-out plastic access door. The door is pivotable between a closed position and a full open stop position in which it is outwardly pivoted more than ninety degrees away from its closed position. A specially designed concealed, break-away hinge structure removably interconnects the access door and front bezel portion and includes a pair of hinge arms projecting outwardly from the door and molded integrally therewith. Outer end tabs in the hinge arms have apertures therein that rotatably receive domed hinge pins within recesses in the bezel. In the event that the access door is forcibly pivoted outwardly beyond its full open stop position the domed hinge pins act as cams that torsionally deflect the hinge tabs out of engagement therewith. As a result, the door simply pops off the bezel without damaging either the door, the hinge structure or the bezel. The hinge arm tabs of the separated, undamaged access door may subsequently be snapped back onto the domed pins, with chamfered edge portions of the tabs initially engaging the domed portions of the pins to torsionally deflect the tabs in a manner facilitating their reconnection to the hinge pins on the bezel.