The drawers have to be closed but there is a stop tab at the back of each drawer if the tab or tabs for that drawer is missing and the drawer or drawers go in too far then it goes past the mechanism and it s the same as if it were open line all the drawers up flush with the face of the cabinet and one drawer will open.
File cabinet drawer won t open all the way.
Papers often become lodged in the top of the drawer especially if the file cabinet is very full.
Some file cabinets have a makeup that won t allow you to pry at them but others are easier to slip tools into.
Pull down gently on the file cabinet drawer if you cannot get it to open at all.
If the drawer doesn t slide smoothly then it may have fallen off the track that lets it open.
Remove anything that might prevent the drawer from closing all the way.
If the drawer slides smoothly then it s one track.
Open the drawer as far as possible.
Use a prybar to lift the drawer up and then slid all of the tracks into place if you can.