Laptop audio whine while charging

[Soylent Joe]

My dad has an Asus G73Jh that we got off craigslist a few weeks back. The GPU is faulty and when it's under load the system shuts off, but that's a separate problem. We hooked it up to the TV to watch a movie with the video going through VGA and the audio going to the AV receiver via 3.5mm to RCA. While charging a quite loud squealing/whining sound can be heard, and there is some faint static horizontal lines in the middle of the picture. When you unplug the charger both effects vanish. I also noticed on a recent road trip that something similar happens with my Acer netbook. While plugged into the power inverter, a squealing could be heard through the headphones.

What could be causing this? Possibly sound drivers or "dirty" power coming from the source or chargers?

 

[robal]

Hi,

Modern chargers are all "switched-mode" type. If they're low quality (or old), they can geterate quite a lot of noise on their output, causing interference and such noise. ("dirty power")

Car 12V -> mains AC inverter is even more noisy, and that's typical.

While I cannot guarantee it, there's very good chance that the problem will go away if you get another charger (same specs!).

Does your laptop use 12V or 19V charger ?
If you use 12V, you can easily bypass noise inverter in car by using direct cable.