i have dell inspiron 3531 so i started after 15 days my laptop so it is not turn on and i tried with out the bettery (only with ac adapter) the it is working correctly. again i insert the better it is turn on until the logo appear and under the logo the message shown PREPARING AUTOMATIC REPAIR and suddenly turn off. and the process repeats And the main thing is when the bettery is inserted and pluggedin (WHEN THE PC SHUT DOWNED) then press the start button and start until dell logo and the message. after that power light blink three time and turn of the pc suddenly. when ever i put the pc on charging the light blinks in a sequence.even pc is not working with bettery only. and whenever pc started with adapter and that time i tried to insert bettery it is suddenly shut down immediately.
It could be the battery needs replacing or it could be the charger is not putting out enough power to both start and run the laptop as well as charge the battery.
If you have another charger (make sure it is the exact same specs) to try on the laptop I would start there. If it doesn't happen with another charger, while the battery is in, then your charger needs to be replaced. However, if it still happens, even with a different charger, then the battery probably needs replacing.
Now if you can't do this yourself (no charger to test, etc.) then you will have to have it looked at. Either by the manufacturer (if under warranty) or by a local tech.