The pins that connect to the sim r damage. There is a tiny switch inside the N9 to recognise SIM. Perhaps it doesn't work properly anymore. Punched SIMs can shortcut. You can open the device following these instructions: http://www.youtube.com/watch?v=i9u7r4j0atU … If you don't dare yourself, let someone do it 4U.
These links will b handy
www.youtube.com/watch?v=a9DG_9OiRdY
http://www.mobilerdx.com/2011/10/nok...ution-exe.html