The phone didn't work. The phone didn't fucking work because it was dead. The chime wasn't from receiving a text, a call, or a voicemail, it was a chime signaling it was dying. Hermione had less than ten seconds to realize this before the blocky letters of NOKIA appeared and disappeared. She couldn't even attempt to charge it with her wand - Something that was more than touchy with a regular wand and a skilled wizard, but was not impossible with her altered wand.