Today I got some condensation on my iPhone 4 and immediately afterwards it appeared that the phone was not working properly. Finally I figured out that the issue was simply that the phone thought that headphones were plugged into it when in fact there were no headphones plugged in. This caused numerous issues including the touch screen sounds to not be heard, me to not hear when people called me though they could hear me, the iPod to not play through the speakers, and any other sounds that you would hear directly through the iPhone speakers. After tooling around with the headphone jack I was able to get this working properly again as explained below.
iPhone Stuck In Headphone Mode Verification:
As you can see in the screenshot above the iPhone thinks that headphones are plugged into the iPhone 4 even when they were not plugged in when this screenshot was taken. I was able to use the iPhone normally with headphones plugged in however sounds were not present with no headphones. Below are a couple tricks to try to get the iPhone headphone jack working properly again.
Plug & Unplug The iPhone Headphones Multiple Times:
This is what I would try to do first to resolve the iPhone headphone jack issue. Simply plug your iPhone headphones into the iPhone headphone jack and unplug them. Repeat this ten times to see if it resolves the problem. You can play the iPod during this procedure to see is heard from the iPhone speakers when the headphones are unplugged during the process.
Clean The iPhone Headphone Jack Port:
In my case since I appeared to have gotten some condensation on the iPhone itself I took a piece of paper towel and rolled it up so it would fit down into the headphone jack to soak up any water or condensation that had formed. It didn’t appear to get any liquid from the headphone jack however it did clear out some dust. I have read where lint or dust being in the iPhone jack could cause the same issue.
Power Off iPhone/Sync iPhone:
You might also try powering down the iPhone with no headphones attached. Before turning the iPhone back on plug in your earbuds or headphones and then power on the iPhone. Once the iPhone has completely booted then unplug the headphones to see if the iPhone recognizes the headphones are unplugged. If this does not work I would attempt to sync the device with iTunes and afterwards see if the iPhone recognizes the headphones are unplugged.
Upgrade iPhone iOS Software:
I briefly had things working properly after the first step however the iPhone went right back to thinking that the headphones were plugged in. Finally a new release of the iPhone iOS was released recently and I had not upgraded yet so I upgraded my iPhone 4 from iPhone iOS 4.0.1 to iPhone iOS 4.0.2 and this ended up resolving the problem. I do not think that it was the actual upgrade that resolved the issue but instead the fact that the iPhone became hotter while syncing, upgrading, etc. and this may have dried the little bit of water or condensation that the iPhone came in contact with.
iPhone Without Headphone Jack Issue:
As you can see above when adjusting the volume the iPhone no longer thinks that headphones are plugged in when they are not actually plugged in. The iPhone appears to be operating normally at this time.