Hello guys. My friends laptop (dell Vostro 5470 i3) won't boot without the AC charger and the battery has to be removed for the laptop to turn on. Also the power button can't be pressed, so he is using a DIY jumper that he made from the cable on the motherboard.
It sounds like either the battery is toast and/or the charger is damaged (even if you don't see it).
I would be leaning towards the charger being the issue though. Why? Because if a charger is damaged in some way, it won't put out enough power to both run the device and charge the battery. Leaving it not wanting to work when the device is on, and the battery is in.
You can try turning the laptop off (completely off not sleep or hibernate) and then connect the charger cord and see if it will charge the battery then.
If yes, then the cord is the problem, and the battery is probably fine, so replace the cord.
If no, then both the cord and the battery could be your problem, meaning both would need replacing.
Before doing any of the physical work, make sure the laptop is no longer under warranty. If it is, you don't want to void it by having anyone do the work for you, other than the manufacturer.