Morning duffers102,
Thanks for using Apple Support Communities.
For troubleshooting on this, take a look at this article:
iPhone: Troubleshooting No SIM
http://support.apple.com/kb/ts4148
If you encounter any of the above symptoms on your iPhone, try these steps to attempt to resolve the issue:
- Update your iPhone to the latest version of iOS.
- Toggle Airplane mode On and Off.
- Try turning iPhone off and then on again.
- Check for a carrier settings update. Tap Settings > General > About. If an update is available, a prompt will appear.
- Remove the SIM Card and verify that it is a valid, carrier-manufactured SIM. Also verify that it is not damaged, worn, or modified. Then reinsert it.
- Restore the iPhone.
If you still are unable to resolve this issue, contact Apple support for further assistance.
Hope this helps,
Mario