Why my computer only charge when it off
and when my ac adpter is plug in my power button flashes
The reason as to why it's not charging when on is because the AC adapter is not on. It is best that you take it to a professional mechanic to get a more suitable solution. The AC adapter is most likely faulty.
i would go talk to a computer person other then best buy because they have horrible costumer service they say its broken then like dispose of it...
try technical help but I think you need a new adapter