Charger making weird noise

The slight noise from the charger is probably normal. The character of the noise may vary depending on what the computer is doing. Scrolling changes the current load on the charger because both the central processor and graphics subsystem consume more power while the screen contents are changing.

I can hear a little noise from my MacBook charger, but it is quite faint. I've heard similar noises emitted by Dell and Toshiba chargers.

Bill

I have the same problem. I would say that it is a little louder than faint. Did you call Apple or anything. I have several issues with my macbook that separately are not too bad, but when they are all added together it is frustrating. I have been waiting to finish exams before I call apple so I might be doing that next week.

I've had my MacBook/power supply for 1.5 years and I just noticed this noise for the first time today. Anyone find out more about this yet?

unfortunately I forgot to mention this problem when I sent my macbook in for repair. I may call them again and see what they say later this week or next week.

As noted in this thread, some noise is normal and it will vary depending on the load on the charger, generally louder under higher load. Right now my MB is fully charged, screen bright, airport on, and I can only hear a hiss in my charger if I hold it to my ear. But I know it's been much louder at times. It can be worth checking what the CPU is doing (with Activity Monitor) when you hear the noise. There could be something using CPU cycles - and thus power - that shouldn't be.

One concern with charger noise is that it can indicate a kink or cut in the cable between the charger and the MacBook. It's easy to catch that in recliner chair mechanics (I've done it) or otherwise cause damage leading to intermittent shorts. This will cause the charger to shriek at its loudest!