Battery Not Charging and Light Not Showing Up Again I just have got a Macbook Pro Retina 2014. The charger is new and 85 Watt.
I have two issues. When I first connected the charger, there was 54% charge on the laptop and for only 1 second the green light of the magsafe turned on. I have seen no more light [orange/green] after that ever.

And, the pc is not receiving any charge when the power cable is connected.  I have different brightness set for battery/power. When I connect the adapter, the brightness changes, the charging sign in the battery shows. But, no change in percentage and It says, "Battery Is Not Charging".

I have tried all the other answers to the similar questions including SMC reset but nothing worked. It seems to me the connection is okay [as brightness changes]. But somehow laptop doesnt take the charge. Not sure what to do. And, do not know why the green light turned only once and never again in the MagSafe.
The first thing you should do is examine and clean the MagSafe connector, both on the cord and on the machine. MagSafe's have five spring loaded pins; if one of the pins is stuck, or grime is blocking a connection, that can cut the power output of the cord, meaning the computer will run but the battery won't charge. Apple says:


  To clean the MagSafe connector and pin area, disconnect the adapter
  from the wall outlet and from the computer. Remove debris gently with
  a cotton swab or a soft bristle toothbrush. Be careful not to get any
  cotton fibers stuck in the pin receptacle and to not bend or otherwise
  damage any of the pins. (see: MagSafe Troubleshooting)


Failing that, this likely needs repair.

The MagSafe board is inexpensive and relatively quick to replace. Next is the battery and all cables, most expensive and difficult to exchange is the logic board.

You would want to replace parts one by one until the hardware issue is resolved. 

Resetting the SMC is a once every 6 months thing, if you do that more often it’s hardware repair that’s needed.