Q: Not reading sim

Hi Yax91,

Welcome to Apple Support Communities!

The article linked below provides troubleshooting steps for a similar issue with iPhones, but the troubleshooting steps are the same for the iPad Wi-fi + Cellular devices.

iPhone: Troubleshooting No SIM

http://support.apple.com/kb/TS4148

Symptoms

In certain situations, iPhone may present one of the following symptoms:

• "Invalid SIM" or "No SIM Card installed" alert appears intermittently.
• Status bar displays "No SIM" when a SIM card is installed.

 

Resolution

If you encounter any of the above symptoms on your iPhone, try these steps to attempt to resolve the issue:

1. Update your iPhone to the latest version of iOS.
2. Toggle Airplane mode On and Off.
3. Try turning iPhone off and then on again.
4. Check for a carrier settings update. Tap Settings > General > About. If an update is available, a prompt will appear.
5. 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.
6. Restore the iPhone.

If you still are unable to resolve this issue, contact Apple support for further assistance.

-Jason