Hello,
got the same problem. I am an electronics designer and know my chargers have enough current, it is rated 15A! So tried making a 5.3V charger, like is mentioned many times. Did not work, so swapped wires, also did not work. So turnes out only the Samsung charger works, independent of wires.. They have some kind of protection...
So what could be the clue... The not used datawires in the USB cable! So i tried connecting them to +5V, to GND, crossed, nothing worked, until I disconnected them and left them connected floating! Red cross dissapeares, and charger works at full capacity.. This is a smart trick of Samsung, since in a USB devices these wires are connected to an output and in a charger they are left floating, but probably not connected to each other... So their own charger is unique!
What to do.. Open charger wire, determine D+ and D- wires (mid two contacts in connector), cut them, connect them to each other at the Tab side, and charge.. If you are not able to do so, buy a stock charger, or wait longer (device off charges faster)...
Have fun!