HP Laptop Power Brick Buzzing?

Well im helping out my uncle fix his laptop

But it won't turn on.

He said it was working fine a few days ago.

But he brought it here. and im looking at it.

I plugged it in and when its plugged into the wall, the power brick part of the power cord is buzzing, Only when its plugged into the laptop itself.

When its out, still plugged into the wall it doesn't make the noise

Im quite positive the battery still works. But it doesn't send a charge after the buzzing noise. But i know laptops will turn on without a battery if plugged in

Its an HP laptop, and the product numbers are:

Power Cord / Brick: - 394224-001
Battery: 432974-001