Diaphragm blades stuck in place

First understand that the blades on the FD lenses will be stopped down when the lens is off the camera.

Quick way to check the lens is to set the camera shutter speed to bulb, Set the lens to manual F22

Open the film back (be sure no film inside) and release the shutter and hold the button down. now the shutter should stay open for as long as you are holding the button. look though the film gate area and hold the camera towards a light. you should see the lens aperture hole very small, now slowly open the lens by slowing moving the ring towards the largest f-stop the lens has. as you do this the opening will get larger. if this works on all your lenses then most likely the lenses are OK. So possible cause could be wrong shutter speed, lens is not in the AE position, Not a high enough ISO for the lighting conditions.

If film is completely blank, I suspect shutter is not opening