Postagem original de: mdavis6565 ,
Actually I am surprised no one has added this answer but this problem can actually come up even with genuine apple chargers. If your docking port is corroded at all then you may get this error although it also could be from non apple products even the cheap 7-11 cables work on my 4s. I tried fixing my 5 with high grade isopropyl alcohol and steel wool but that did not work. I ended up getting it repaired for $55 which I think is probably a great price but I live in a low income neighborhood so services are probably cheaper. Anyway my guess is your docking port is bad. Try cleaning it first then get it repaired.