"How do I put my iPhone 3G in DFU Mode?"に関する回答When you are stuck on iPhone dead or loop screen, you can use recovery mode to fix this instead of resetting it because reset would erase all data and settings so you may lose your precious data. if you use recovery mode, you don't need to worry about data loss. You also don't need to press home or power button if you use the famous tool used to enter and exit recovery mode called ReiBoot. It is straightforward, totally free. If needed to try, download it here: Download ReiBoot.
"iPhone always reboots after 3 min of use, NO IMEI, NO BLUETOOTH [...]"に関する回答Use freeware iPhone Care to fix it！ Features of Free iPhone Care: 1. Fix all iOS issues 2. Optimize iOS system for best performance 3. Speed up slow devices & apps 4. Slim down iOS devices and free up space 5. Wipe and secure sensitive data
"Got in pool with iPhone in pocket"に関する回答Read this guide to learn how to get rid of your wet iPhone.