Cabinet drawers usually work by sliding along a set of drawer guides. The guides, made from metal U-channel strips, accommodate rollers fastened to the sides of the drawer, allowing the drawer to open and close. As the drawer fills with more objects and is continually opened and closed, contents shift, causing one or two objects to fall out of the back of the drawer box or to stick up. This prevents the drawer from closing fully. Alternatively, the slides may be defective.
Open the drawer as far as possible. Look in the back for any contents in the drawer box that might be sticking up or out the back of the drawer box, preventing it from completely closing. Remove anything that might prevent the drawer from closing all the way.
Find the tab stops on either side of the drawer and push the tabs in with your thumbs. Pull out the drawer and put it on top of the counter temporarily.
Shine a flashlight into the recess. Look for any objects near the back of the recess preventing the drawer from closing. Pull them out, if any obstructions are present.
Unfasten the drawer slides on either side of the recess where the drawer fits using a screwdriver. Pull the drawer slides out of the recess after removing the mounting screws. Look for kinks or warping, preventing the drawer from closing. Fix or replace, as necessary.
Hold the drawer slide against one side of the drawer recess, aligning the pre-drilled holes in the slide with the holes in the drawer recess. Fasten the slide with a screwdriver and screws. Then repeat the drawer slide installation on the opposite side.
Insert the rollers on the sides of the drawer into the slides, aligning them, allowing the rollers to roll inside the U-channel. Push the drawer back into the recess. The drawer should now properly open and close.