Power draw when shut down???

I have been noticing in the last few weeks after getting my laptop back from repair, that my laptop is making a high pitched noise that is associated with power being drawn from or added to (charging) the system. While this is very annoying, especially at night, the most concerning thing is that this occurs when the laptop is shut down and in hibernate, where the computer is supposed to *draw no power*. The only way to get this noise to stop is to pull the battery out and take the computer off AC power.
I have found that if I leave it in hibernate or off, and then turn it on a few hours later, the battery will only have 85% or left left (starting with 100% after charging for most of the night).

So my computer, when turned off, really isn't turned off, and instead makes noise loud enough to wake me up in the middle of the night. WTF Not cool. Does anyone have any ideas of why this is happening?

EDIT: on second thought, maybe this should go in the hardware forum.

 

Sounds like a leaky capacitor to me. The repair guy might have been careless and accidentally struck something on the motherboard or something.

 

Would that entail a motherboard replacement? I've already had the mobo replaced once....