MacBook Pro not booting

My 15 inch MacBook Pro (A1398, EMC 2876) is not getting charged and not booting. I get following screen when I turn it on:

When I connect my charger, it first turns green and then orange as usual. However, the charging port doesn't heat up as it normally does.

The original had stopped working as some of it's pins had turned black. However, I was able to charge this laptop with charger of another 13" MacBook Pro. Some time later, it stopped charging at all and didn't boot. After I noticed some of the pins in the laptops charging port also had turned black, I replaced the charging port myself. However, this also didn't seem to fix my problem. The state of laptop is same as before changing the charging port.

Please suggest a solution.

Thanks,
Aniket