Couple of iPhone 4S owners are experiencing serious issues with their recently purchased iPhone 4S where the ‘SIM Failure’ or ‘No SIM card installed‘ is being displayed, when the SIM card is installed in the slot.
According to some of the users, the problem can be re-produced by using Siri assistant for a long time, where the iPhone 4S becomes hot and eventually fails to recognize your SIM card and throws SIM Card failure, and bad SIM messages on your homescreen. Is it? we don’t think so. Perhaps, it is not even a bug in iOS 5.0 or iOS 5.0.1 which is causing trouble in recognizing the SIM card.
It is actually the design flaw within hardware. The card tray eject mechanism is causing a short circuit with the SIM card contacts resulting in the SIM failure. Just follow the steps in order to fix it.
Fixing iPhone 4S “No SIM Installed” Problem
Step 1: Eject the SIM card tray, In order to eject it just insert a needle or a paper-clip into the tiny hole on the right.
Step 2: Place a small piece of tape to the side of the SIM tray as shown on the picture below which will prevent the top part from making a conductive contact with the SIM card.
Alternatively, you can place the tape on top of the SIM card as shown in the image below. This will prevent the short circuit as well.
Second Method: If the above method doesn’t work, try switching out the SIM tray of your old iPhone 4′s with the new iPhone 4S tray. The latest model has slightly thinner tray which could be causing the issue. The second method is working for most of the iPhone 4S users.