Power cord turns computer off

The input jack that is soldered to the motherboard (where the AC jack plugs in) probably has a cold solder joint. Thus the laptop switches from battery to AC power. You can try to have the solder joints
re-soldered.

Since you have already replaced the battery and the laptop works with the AC charger, then probably the charge circuit in the system board (mother board) is bad. I have rarely seen an AC charger that will power the laptop but not charge the battery. 99% of the time, if it is not the battery, it is the system board.

You just want to refresh battery from the BIOS. There problem will be solve

remove the battery and insert again. if it continues then you will have to check the power source perhaps current it not enough for charging, if it continues then you will have to get a new battery

Hi,
As a first step, Try reseating the battery on the laptop and see if the problem is resolved.
If not working, then try flashing the BIOS on the laptop.
You can find the latest BIOS for your system in the support.dell.com website.
1. GO to support.dell.com
2. Click on "Drivers & Downloads"
3. Either select your System model or enter your the service tag of the computer.
4. Under the "BIOS" section., you will find an option to download the BIOS.
5. Save it to your system., and just double click it, to install.

-> Make sure that the system is not turned off while Updating the BIOS...

Have a nice day

you may have damaged the power input port.
broken solder joint. or your power supply took a dive. if you have a DMM 'meter' check the power supply to see if you are getting power from it.
if it is the power input port, you will have to either open up the laptop and see if it is a fixable soldering job or take it to a pro.
Happy Fixing =)

Hi
Update laptop bios go dell.com check for update of your laptop model....
Thanks

maybe..or it's deeply discharged..you may need to run the computer, sans the battery, then install battery while the computer is up, and then do a full recharge.

You can also pick up the batteries less expensive than most computer places at batteries plus. And yes it sounds as though it is the batteries charge is getting low, especially if it runs fine when the battery is out and you have it plugged in.