HP 840686-001 is a hinge cover for the display assembly of 14-inch touchscreen products. It is a replacement cover for the hinge area, identified in HP’s service documentation by this exact spare part number.
The part is listed among display assembly components for the HP ProBook 640 G2, 645 G2, 650 G2 and 655 G2 service guide. Its touchscreen designation distinguishes it from the separate hinge cover listed for standard 14-inch products.
HP’s service procedure specifies removal of the hinge covers with two M2x5L P1 screws, followed by replacement in reverse order.