Way back in 2006, Apple posted a troubleshooting assistant for iPods dubbed “the 5 Rs”: Reset, Retry, Restart, Reinstall, Restore. The procedure used an escalating series of steps that solved a majority of issues that afflict the device.
Based on reader reports of iPhone 4 troubleshooting issues, we’ve compiled a shorter “4 Rs” list of escalating fixes that can solve a surprisingly large number of iPhone 4 problems.
1. Reboot (hard reset). This may yield success for slow 3G data transfer and other issues. Hold down the sleep/wake and home buttons simultaneously for roughly 15-20 seconds, until the screen powers off then an Apple logo appears, which signifies a reboot. Some problems may require (oddly) that this procedure is performed twice.
2. Reset all settings. This may resolve proximity sensor issues, slow throughput, FaceTime problems, loss of cellular service and more. It appears that the reset may restore disengaged hardware components and clear corrupt data that prevents proper connectivity. Navigate to Settings > General > Reset > Reset All Settings. Note that this will erase stored messages, passwords and other information.
3. Restore, but not from backup. This procedure can resolve app crashes, unexpected resets during phone calls, battery drain and more. It appears that bad holdover data from iPhone backups (especially those created for previous iPhone models) can cause various issues. Restoring as a new phone will delete contacts and other data, but may resolve the problem. To do so, connect your iPhone or iPod touch to your computer, click “Restore” in iTunes, then choose “setup as new phone.”
4. Reseat your SIM card. This fix is effective for some data throughput, signal or cellular service issues. Simply remove your SIM card, clean it lightly using a dry cloth, ensure that there is no debris in the SIM slot, then reinsert the card, ensuring a snug fit. Instructions for doing so can be found in this Apple Knowledge Base article.