"iPhone 5s - Infinite boot loop (after screen replacement)"に関する回答I just replaced screen on an iPhone 5 (not 'S') phone myself. New bat sorted it. It was boot looping, I put it into recovery mode (screen showing usb+iTunes logo) but it would error 21 on pc iTunes, and 2001 on mac iTunes. (strange that they read differently) I then realised I had damaged the battery cable. bought a new cable and the restore worked! HURRAR! note: without the battery installed, the restore will not work.