zSkeptic wrote:
Regarding this battery drainage issue, there are only 2 things I know for sure. First, no one on this forum (or any consumer) really knows what the true root causes are for extraordinary battery drain. Second , we really have no idea how widespread this problem is.
....
Maybe some people on this forum have experience in microeletronics and they can tell us more.
Look here what cel wrote:
ce1 wrote:
Add me to the list. Bought my iPhone 4S 16GB White and several hours later noticed the issue. Once you know it's there, it becomes even more prominent. Got it replaced and the replacement has the same issue. Also, a friend just purchased his 4S a day before mine and I tested it and can confirm the issue exists with his phone as well. He purchased his from Best Buy, my orginal was purchased at AT&T and replaced at the Apple store.
Venturing a guess, it appears as though all iPhones are affected. It seems almost impossible for so many of these units, all purchased at different times and locations, to be affected in such a consistent way. The majority of users probably do not notice the static either because they can't hear it or think it's normal or simply don't want to appear crazy. When I took it to the Genius Bar the woman dialed the phone from a house line and swore to me should could hear no static. When I took the phone from her I heard it immediately, but that's because I knew what to listen to. I work in the microelectronics industry and when integrated circuits make this kind of noise, the issue tends to be related to (1) incorrect voltage or (2) a faulty component. Faulty components can continue to work within expected parameters, but will emit an electronic buzz/humm/static/whine/crackling. I'm doubtful that Apple can ever solve this issue with a software fix, but they may be able to fix it by identifying the issue and fixing it in their future production. At that stage it's probably going to be worthwhile to get a replacement -- assuming that Apple's service stock has caught up, which is definitely not going to happen for a while even after the issue has been fixed.
and he wrote it here:
https://discussions.apple.com/thread/3393647?start=705&tstart=0