Battery buzzing / humming noise

I got my Z96Js last week. Works great.

However, the last few times I have run the laptop on battery power, there has been a buzzing/humming noise coming from near the rear USB ports. It happens a few minutes after I start up the laptop only on battery power; the noise appears a little quicker if I unplug the power cord while the laptop is running.

Did I just get a bum battery? Or is the problem on the motherboard?

 

Did this just start to occur? Restart the laptop, does it happen with the battery is in, while on AC.

Does it occur when you are on the battery?

Try to disable the USB ports, using the device manager and see if that stops it.

How about placing a USB device in the USB slot.

Try your headphones in the headphone jack to see if there's any interference.

Try a Bios update. Maybe even a graphics driver update.

Have a look some of these suggestions. This will help differentiate what's going on.

 

are you sure it isn't the cpu? core (2) duos have been known to emit a whining noise when it enters the c4 sleep state...which is where your computer spends most of the time when you are running on battery power......

 

my friend actually has the same problem as well but on a z35f. The buzzing comes on soon as it runs on the battery only.

 

try this (rmclock section) and see if it gets rid of the sound.

http://forum.notebookreview.com/showthread.php?t=115051

 

When I unplug the A/C cord, Power4 Gear goes into "Quite Office" mode.

 

I've pretty much located the noise to being right behind (or just to the right--when facing the the backside) of the USB ports.

I assumed that the fan is located right behind the vent (noise is definitely not coming from there--just warm air). Am I wrong?

 

i actually meant c3, not c4. anyway, the fact that it goes into quiet office mode has nothing to do with it. the c3 state is a power saving state. if you want to chart it, run perfmon from the start menu and add the c3% counter.

the whine from the cpu is due to resonation so the sound may not come directly from where the cpu is but whatever parts will resonate at that frequency.

 

Once I unplug the A/C cord, perfmon shows C3 as hovering between 90-99%.

 

as expected.....when you scroll using the up and down arrows, does the sound stutter, by any chance? anyway, i would suggest trying out the rmclock fix. you don't even install the software. another possible fix for cpu whine is disabling the ability of your usbs to power down when on battery.

if this doesn't solve your problem, i guess this isn't a cpu whine problem and don't know of another component that makes a buzzing noise....