Doors and Windows - Single Action Spring Hinge - How to repair

I have a door equiped with "single action spring hinges".
The spring hinges do not work now.
Can the hinges be repaired?
If so, how?
Please advise.
Thanks

I have seen these hinges installed backwards, which causes the spring to bind against itself and eventually break. You would need to replace it if it were broken. However you may have only lost the pin which holds tension on the spring. Then all you need is an allen wrench and a piece of trim nail to fix this. First make sure the hinge is installed correctly. The directions for the hinges I used said to put the Underwriters Label logo against the jamb. Then tighten the spring. There should be a hole somewhere on the hinge to put the piece of nail into, although it would be preferable to use the pin that comes with the hinge. The pin holds the spring in a tensioned position. These hinges are typically used in fire rated steel doors that allow access to attached garages from the living space. And let me tell you, they do a number on your fingers if your not careful. Be especially careful with little small children and these types of hinges. They are used in accordance with many local codes.

Thanks for the info, but it didn't seem to work.
The hinges were indeed originally properly installed with the "Underwriters label logo" against the jamb.
I removed the pin which holds the spring in a tensioned position and tightened the spring with an allen key. While I held it tight, I re-installed the nail pin in the hole to hold the spring position.
I did this for both hinges as I have a door which leads from the house to the garage. This door has three hinges of which 2 are single action spring hinges.
Did I miss something or not do it correctly?
Or is the spring gone and needs to be replaced? If so, can I replace just the spring or do I have to replace the complete hinge assembly?
Let me know. I appreciate your advice or that of anyone else that has experienced this.
Thanks