RE: Battery not charging after power adapter replacement
The battery not charging may be an issue with the adapter, battery, dc-port - where the adapter is plugged in or the motherboard itself.
Where have you procured the adapter from? Is that an original Dell adapter for this system model? Is the adapter frayed? When you connect the adapter to the machine, does the adapter stay in firm or does it fall off easily?
Update the BIOS - http://dell.to/1XySXNb - restart the system and check.
Check the battery health status in Dell battery meter.
Remove the battery and check the battery health using the charge status button:
(To check the battery health using the charge gauge, press and hold the status button on the battery charge gauge for at least 3 seconds. If no lights appear, the battery is in good condition and more than 80 percent of its original charge capacity remains. Each light represents incremental degradation. If five lights appear, less than 60 percent of the charge capacity remains, and you should consider replacing the battery.)
Restart the system and press f2 key to enter BIOS - check the adapter status in BIOS with and without the adapter connected. Also, wiggle the adapter jack at the end when connected to the system and check if the adapter status changes at any point in BIOS.
Restart the system and press f12 key on startup - choose diagnostics. Let it run the diags and if you encounter any errors - make a note of the complete error and report the same to us.
Keep us updated.