Carl - Typically, the back panel that comes with that kind of cabinet is a piece of shit which offers virtually no strength or support and ultimately leads to a short useful life of the cabinet.

If you can, replace the back panel with a piece of 1/4 plywood. Use Elmer's carpenters glue or similar and screws or nails. Lay the cabinet down on its face, after removing the door handles, then glue and screw the back panel. The screws/nails are only going to hold the plywood in place while the glue dries. It's the glue that is actually holding that together, so make sure you do a good job of the gluing. Leave the cabinet face down until the glue dries. 24 hours is a good amount of time for that. If you do this, your cabinet will be very strong and last you a long time.

PC :thumbsup: