The power jack socket is located inside the laptop and conducts power from it to the electronics of the laptop to charge the battery and power the laptop. When a fault develops it is often difficult to be sure of the cause, this article will indicate some of the things to check to arrive at a conclusion.
You may notice any of the following that may be caused by a faulty power jack located inside the laptop:-
1. Laptop completely dead no power lights etc. This can be caused by no power getting to the laptop or almost any other fault affecting the power up sequence of the laptop. If you have another laptop of the same model and make you could try swapping the battery with a fully charged battery. If the laptop then powers up then the fault is probably with the power jack or charger. Alternatively, sometimes gently wiggling it will cause the charge lights etc of the laptop to briefly illuminate. This would again indicate a failed power jack.
2. Laptop comes on then cuts out after a short period. Again several faults could cause the laptop to quickly cut out; however, a faulty power jack would commonly cause this. When the power jack contact make a poor electrical connection, heat is often generated causing the connection to terminate.
3. Laptop comes on but battery will not charge. Often when the power jack fails this is caused by one or more solder pads cracking; this can result in a high resistance electrical path. This will in effect limit the maximum current that can be delivered to the laptop, so the laptop may come on but there is not enough power left to charge the battery.
4. Laptop works until or unless the power connector is wiggled. Very much like the last fault except the solder pads make and break connection when it is wriggled.
5. Battery charges when laptop is turned off, but not when it is turned on. This is very much like fault 3 as not enough electrical power can be delivered to both the laptop and battery.
6. Smell of burning or hot power connector when plug removed from the laptop. When one or more solder pads connected between the power jack motherboard fracture a high resistance electrical contact may be produced. When current flows heat will be generated possibly resulting in component or motherboard burning. This is perhaps the most destructive failure as it often completely destroys the motherboard due to the considerable heat generated. The repair will either be impossible or corrected by using a nutted power connector that uses flying leads to bypass the burnt motherboard.
7. Light on laptop power supply dim or flashing when connected to laptop and normal when not connected. Most laptop power supplies have a safety feature where they will dim or flash the power light to indicate that there is an overload condition inside the laptop. This will often occur when the laptop motherboard is starting to smolder as the motherboard, which should be an insulator, turns into a conductor due to carbon production.