Help! My phone will not play sound when an app is open?!

Question

Seemingly out of the blue, my iPhone stopped playing sound through the external speaker. This began about a month or two ago and I have been unable to fix the problem. The sound will play through the external speaker until I open another app (safari, camera, etc.). The sound used to work through headphones until this morning. Now the sound won't work... At all! I brought my phone to an apple store a week ago and the first guy checked my phone with a flashlight and told me first that there didn't seem to be any water damage. Then, some other technician helped me. He opened iTunes and miraculously, the song played! I couldn't believe it was magically working. He explained that it looked like my dock connector was looking a little eroded and that is why the sound doesn't work. He said he could try to brush it out and that should fix the problem. Tried my phone later... Volume doesn't work anymore! The dock connector works fine otherwise, I am still able to charge my phone. My phone will not play music via bluetooth speaker. I talked to multiple people on the phone who all seem to think it's a software problem... I am really not understanding what is going on with my phone! I have googled this problem many times in the last few months and most people say that it turned out to be a software issue. I have checked both water indicators (in the dock connector and the headphone plug, right?) with a flashlight and I don't see any red... Any insight or ways to fix this would be very appreciated! The whole thing makes no sense to me.

Answer 1

Are you using an APple charger or a thrid-party one?  I ask because if you are using a third party charger, it may not be wired properly and it may be telling your iPhone that the cable connected is also an audio interface so your iPhone may be sending the audio signals through the cable to the charger.  I have a charger in my truck that also doubles as an FM transmitter so I can play my iPhone audio through the truck radio.  Your charger may be doing something similar, especially if it is not an Apple charger.