Monitor Display shifted to the left ?

The display on my Dell 18" Ultrasharp monitor is shifted to the left.  There is a complete blank (Black) area on the right side of the screen running vertical.  The area is about 1/4" wide.  The display ( Text, Pics etc...) is off the display area on the right side of the screen also in the vertical direction.  I cannot fully see the right side of the display.  What's wrong and how can I fix it  ?  I might add that I did order a "Refurbished" monitor but the rest of my system is brand new.