Hi Qasim,
I don’t think that your problem is the charging port if the laptop works from the adapter.
There is most likely something wrong with the charging circuit and/or the charging IC. I attached a couple of schematics from a similar model (840 G2), they don’t tend to vary in huge detail. The concept should be the same.
On the first image U6000 is the IC that talks with the charger on the bi-directional data line SDA_BAT_CHG. I would start looking around those lines to see if there is a damaged component or a short circuit to ground.
[image|2325761]
[image|2325762]