Please note if you hear a clicking noise while the camera tries to pop-up the flash you may suffer from a sticky hinge![br]
Gently pull up the flash while pressing the flash pop up button, this should work to open the flash.[br]
Now looking in the pop upped flash compartment you will find two tiny Philips head screws, remove these two screws, towards the hinge you see two openings, gently push there where the two openings are and the flash cover should come of.[br]
Facing the camera from the rear you see a hinge screw and spring. Just carefully loosen the hinge screw and remove the screw.[br]
Clean the screw and clean the hinge housing using a wooden toothpick.[br]
You may use some grease, a minimum amount and fit the hinge screw back.[br]
Some people may suggest to use WD40 or similar, I do not recommend this! [br]
Test the flash popping up and if fine reassemble the flash in reverse order and all should work fine. [br]
Enjoy your Canon 7D, regards Frans