Pull cords are all pretty similar so if you've seen one then etc.....
Does the cord retract?
If it's a broken spring then the pull cord would not retract.
If it is retracting then it's probably dirt, grass clipping interfering with the spring loaded locking lever.
Either way the only way to be sure is to remove the top cover and inspect it visually and clean it out and spray some lubrication on it.
You should be able to do this without taking apart the actual cord and retracting coil spring. It should come off as a unit.

Once you have inspected it if you you have any other questions please let me know.
Hope this helps.