Not sure if the power jack is bad? Try a power jack tester.
My latest laptop came in the shop with the customer reporting a bad power jack. After taking apart the the entire laptop and finally getting to the main board the jack looked fine. Often you can tell a bad jack just by looking at it. They may be loose or disconnected all together. They could look burnt around the motherboard or inside the actual jack. What happens when every thing looks good? This customer insisted the power jack was bad. I didn’t think so.
If you have ever replaced a power jack before you know it can be difficult on some models. This model was not too hard, but I didn’t want to do the job if I didn’t think that was the root cause. I suspected a failed main board.
What you can do to test the power jack is detailed in the following information. Go to Radio shack and get a size N adapter. Solder two leads onto the adapter, one for power and the other for ground. Attached the power lead to the power source end of the jack and the other end to the ground.
This allows you to hook up another working jack with out all the work of removing the old jack. Especially if it’s not bad.
Use a multimeter to identify which lead is the power lead and which lead is the ground. Power usually is the middle lead in the group of holes on the motherboard. If comes directly off of the main pin inside the jack. NOTE: Some jacks are switch like and use flexible peices of metal in the back, and the lead may not be the middle. Use a multimeter to check for continuity from the jack to the opposite side of the motherboard.