I'm assuming you hear the sear letting go when you pull the trigger, but there's no dimple on the primer? Pull the bolt apart, clean everything, inspect the firing pin and put it back together with NO lube or grease. These bolts come apart pretty much the same as a Mauser 96 or 98 - pretty easy job.
If the you don;t hear a click when you pull the trigger, check that your safety is disengaging and that the sear is catching the firing pin. this process will be different for a 1600/1640 (side 2-position safety) and an older FN Mauser action (2 or 3-position safety on the bolt shroud). You didn't specify which you have. The mechanics are pretty simple either way, and there are lots of you tube videos on disassembling mauser bolts.
Good luck