Are you having the infamous "No SIM Card Installed" error on your iPhone 4? This error is such a hassle, and is caused by a design flaw. The iPhone 4 uses a new SIM card called a "micro SIM" and apparently the tray that it sits in does not keep it in place. The SIM shorts out when it touches part of the tray.

What's the fix? A little scotch tape worked for me. Check out this photo (sorry for the poor quality, taken with the iPhone 4) and you'll see a little piece of scotch tape on the SIM. Since installing the tape, I haven't gotten the dreaded error once.



Proceed at your own risk, but I'm happy with the results. No more iPhone 4 sim problem for me.