Removing rust from iPhone dock connector and dock-USB cable (UPDATED: Don't spray directly!)
UPDATE
DO NOT SPRAY CLEANER TO iPhone DIRECTLY. If you do, the water-tamper detection sticker will change from white to blue, which will void your warranty.
I had known that issue so I didn't spray to iPhone and a cable directly. I had a piece of cotton damped with only low DN5. Then wiped rust off very carefully.
Thanks Eido.
Matter
Message "This accessory is not optimized for this iPhone" pops up repeatedly.
Resolution
Clean dock connectors of both iPhone and dock-USB cable. I used Caig DeoxIT® DN5 spray.
Details
Some kind of water might be in dock port of my iPhone or 30pin terminal of a dock-USB cable. And it perhaps caused a short circuit when I connected them to a power source; USB port.
Then that cable became not working. It didn't let any devices to be recognized, moreover 30pin terminal got a fever higher and higher while it's connected to power sources.
I went to Genius Bar in Apple Store. A staff found that rust (or patina?) was stuck to both iPhone and cable. I guess iPhone had detected it as an accessory so that it showed the message. He advised me to clean up my iPhone's dock port exactly.
So I did it with DN5, cotton and Japanese toothpick. Then iPhone and the cable became fine again. Well-done.
