Looks like a surface-mount resistor. Picture is a bit blurry! 
if you can't / don't-want-to RMA it you could try find out what resistor/component went in there and solder on a new one - best to find a friend who works somewhere likely that stock a range of surface-mount components, otherwise I'm sure a boxful could be bought from somewhere like maplins or rs. They're a pita to mount and it'd be messy, and void most definitely void any warranty but it could be worth a shot if you cannot RMA it or have the RMA refused.
Are you sure something did break off? often there are unused mount points on motherboards and other PCBs which are left there for testing or optional components etc etc.
good luck!

if you can't / don't-want-to RMA it you could try find out what resistor/component went in there and solder on a new one - best to find a friend who works somewhere likely that stock a range of surface-mount components, otherwise I'm sure a boxful could be bought from somewhere like maplins or rs. They're a pita to mount and it'd be messy, and void most definitely void any warranty but it could be worth a shot if you cannot RMA it or have the RMA refused.
Are you sure something did break off? often there are unused mount points on motherboards and other PCBs which are left there for testing or optional components etc etc.
good luck!