So, I posted a while back and have looked at all the suggested posts but my battery won't charge on any of my chargers.  It was suggested to replace the power port, Dell calls it a power input jack with part # 6KVRF.  And if that doesn't work to replace the motherboard.  I have since put a new Dell branded battery in it, replace the power input jack and the motherboard.  It still doesn't charge.  I found my docking station and stuck it on there and it charges fine.  BIOS always shows Unknown for the connected power supply.  I have tried several different power supplies.  This doesn't make sense to me anymore.  Normal diagnosis would point it to the power port since it does charge on the dock.  It has been on a power supply for 2 weeks now and I use it sitting in the easy chair and battery level has dropped down to 32%.  Any ideas?  Anyone?  Bueller?