I have an iPhone 4 (Verizon, Model
MD146LL) and I just upgraded from iOS
5.0.1 to iOS
5.1 (9B176) using Settings > General > Software Update.
Immediately after completing the update, I noticed that my phone did not make the unlock sound as I unlocked my phone. "Oh, the volume must be down", I thought. So, I made sure my mute switch was off and pressed the + button to increase the volume. Unfortunately, I was greeted by the empty ringer volume popup:
"Apple must have changed the default setting for the volume buttons
^^"... Surely, I could change it myself! So, I head over to Settings > Sounds:
Oh, the settings are right. Hmm... What happens if I move the volume slider?
Ok, so my phone can play audio. Can it play music or watch a video?
Hoping that this was just a temporary glitch, I tried the following:
Change with buttonson and off
- Turning my phone on and off
- Hard reset (holding Home+Lock until it reboots)
- Plugging and unplugging my earphones
- Plugging and unplugging the USB charging cable
Plugging and unplugging the USB cable seems to fix the issue. However, as soon as I lock the phone, the sound and volume controls are disabled again! Due to this behavior, I'm convinced that this is a software bug and not hardware related (e.g. faulty headphone jack).
Has anyone else experienced this? I'm afraid I'm going to have to do a clean restore or downgrade back to iOS 5.0.
Settings > General > Reset > Erase All Content and Settings was unsuccessful, even when setting up the phone as a new device (no backup). The bug is still present. I will be trying a clean restore from iTunes soon.
Restoring as a new device using iTunes was also unsuccessful.
:( From my research, it looks like this bug not specific to my model:
After further analysis and comparison, I think that this bug is related to the External Accessory Framework (or similar components). When you are plugged into a compatible device, the controls are hidden, similar to my screenshots above. This may also explain why plugging and unplugging the charger temporarily fixes the problem. "I'm unplugged; I should enable my volume controls now."