My Acer laptop wont stay on for longer then 5 secs?

my laptop had a problem to where the wires on the power jack came loss and would not get any power to it so i took it apart then fixed that but now when i go to turn it on it runs for 5 secs then turns off i dont know if i just need to get a new jack or i messed something up inside when i took it apart if anyone has any idea on what it could be feel free to tell me thanks :)