Wont recognise battery

Those may have 1 or 2 different problems.

Cold Solder joint on Mobo.
Bad DC Power Jack.

1: if it is the Cold Solder, you can reflow the solder and be done with it.

2: if it is the DC power jack, It should be replaced.
For simplicity lets call them DC(A) and DC(B)
There are 3 connections to it. Gnd, DC (A), and DC (B).

When the powersupply is plugged in, contacts (A) touch to send +DC to the laptop. (B) is open.

When the laptop is using battery power, contacts (B) touch to send power from the battery through the system.

Over a period of time (inserting and removing the DC Power Cord), the contacts become fatigued, or oxidized and the DC(B) never closes - so it won't work from DC Battery.


RATE ME - if it helps