Well, I got an iPhone 4 with a boot loop problem, and I thought I was able to fix it, but here I am beggin for help: When it is plugged to the wall for charging, it would only show the emergency calls, but not go further. If I unplug the cable, no signs of life. When I plug to iTunes in DFU mode or recovery mode, it downloads immediately downloads the right firmware, verify with Apple, prepare for restore, and then it starts again verifying. When the 2nd verify starts, then the phone starts to boot loop on apple logo for 10s, then black for 5s, and after 5 minutes iTunes gives some error: sometimes 1600, 1611, 3194, and finally 1602. I tried to connect to another PC as well, using a direct USB original cable plugged on PC, but the phone gets in boot loop and therefore iTunes thinks there is an issue (last is 1602). Is there any way to check what's wrong in my phone? Any tool to check if it boots properly and files are in good order? Or to check if battery must be replaced (before actually spending 50$ to replace it..)? I know nothing about the phone, just that I want to install the stock IOS 5.1.1 !! Thanks for any kind of tiny help!