Motherboard shorted or AC adapter is broken?

[MikNomis]

Hello,
my laptop doesn't turn on and the AC adapter dimly blinks when it's plugged in to the outlet. It blinks dimly whether it's connected to the laptop or not, and it never displays a solid light.

I have read that these are symptoms of a shorted motherboard, but also of a broken AC adapter. How can I find out which it is? I don't have any other working AC adapter that I can test on my laptop.

Thanks in advance.

 

[COLGeek]

Do you have access to another, working, compatible power supply? If so, that is your easiest way to check.