iPhone 4S Dock/motherboard problem does`t recharge with 4S connector

Hello I have a problem, this happened to me with 2 iPhones first was 5 now 4S... The problem starts every time the same - I get a new dock connector -iPhone 4S works okay, then suddenly home button stops working... a while after that, dock connector recognises the cable but the iPhone 4S isn`t capable of recharging the battery with 4S dock and even computer doesn't recognize it... this is really strange I bought like 2 dock connectors, the first one doesn't recharge and the second one leaves home button... I use on my iPhone 4S Dock connector from iPhone 4 - it works only to recharge it while the telephone is in state it is booted and working... Other thing is that When I try to boot the telephone over dock and not mainly by the battery, it gets stuck on recovery screen and iTunes tells me that my iPhone build isn`t legible for any updates or what, the same thing happens when I force it to DFU...I mainly thing this is a motherboard problem that it short-circuits the dock connector so it cannot recharge the battery and it blast off but maybe I can solve this problem on my own. Thanks for any answer.. much appreciated...