iPad 2 not charging, unless you do a hard reset first HELP

helloo.

my ipad 2 stopped charging about a month ago on the mains charger. I borrow a fresh cable from my sons iphone but no improvement. I then borrow a whole new charger / cable from a friend, still no improvement. Found on a community site a suggestion to hold down the 2 buttons together until the apple logo appears on the screen (some kind of soft reset) and this worked! So that is where I am... the only way to get my ipad2 to charge is to reset it. Any help greatly appreciated.