Sometimes the solutions to technical problems are not technical at all.
The standard iPhone headphones are quite basic and their sound quality is mediocre. However, they do have a really nifty feature, which is that the in-line microphone doubles as a squeezable button to pause music, advance to the next track, or to answer or end a phone call. It’s quite convenient. I was thrilled to find the Etymotic HF2 headphones, which add the same feature to high quality earbuds. They worked extremely well for several months when suddenly the left earbud stopped working. After some over-the-phone diagnostics with the technical support, the company agreed to replace my set with a completely new pair for free (as a side note, technical support at this company seemed to be one person…when I called early in the morning, I was told “she’s not in yet”).
This morning, the very button that I was so happy to find on these headphones stopped working. Dismayed, I prepared to make another call to Ms. Support, but first did a little detective work. Since every other person in my office seems to have an iPhone (and a couple even have the HF2s), I grabbed a neighbor’s headset and found that it, too, had a non-functional button when paired with my iPhone but both it and my own headset worked fine on his phone.
After lengthy exploration (yes, I should have been working), I discovered that lint had made its way into the bottom of the headphone jack and was preventing proper contact. If your headphone jack is clean, you should see a white circle at the bottom of the jack if you hold it up to the light (this is on an iPhone 3G – haven’t tried it on the old one). If you can’t see it or if its partially obscured, you’ve got lint. An extended paperclip and some digging removed the offending lint and my iPhone is back to normal.