If, before you lift the lid off the bag, the latch "overcenters and stays in the unfolded position, the spring is broken. It is a little coil spring on one of the hinge pins and is hidden by the fabric snubber. The hinge pin can be pulled out of the hinge, the welding at one end of the hinge is NOT welded to the hinge pin, but functions as a stop on that end. On the opposite end of the hinge, the hinge is bent slightly flat. Using a flat blade screw driver to open than bend a little will allow the hinge pin to come out. The pin must be started by using needle nose pliers by the little coil spring and pushing just a little at a time, once the pin clears the end of the hinge, it can be pulled out the rest of the way. The hinge pin only NEEDS to be pulled out far enough to release the old spring and allow you to insert the new one. Then push the pin back in. It is a "fiddly" job which may well try your patience. My replacement springs were $1.79 each from the dealer. Many believe that surface rust causes the springs to break, I think it is fatigue. Keeping a film of oil on the springs may lengthen the time before the next failure. OR, lock the bag before you ride.