cjpaul
1 Copper

Dell Inspiron 15 7000 - Buzz/electrical noise (hard to describe) when connected to AC

I notice an electrical/buzzing sound when my laptop is connected to the mains.  The noise isn't coming from the power supply but from the laptop itself.  This noise coincides with CPU activity which leads me to think it may be 'CPU whine' but if that's the case I don't understand why there is no noise when running from battery.  My model has SSD storage so not expecting any noise to be coming from the HDD.  Any ideas as to what might be causing this?  Thanks.

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5 Replies
mikedo7
1 Copper

RE: Dell Inspiron 15 7000 - Buzz/electrical noise (hard to describe) when connected to AC

Just received mine today (4K 16Gb RAM and SSD), and I have the same issue here.

There is this annoying buzzing/screeching/scratching noise like an old hard drive would do when busy and it is coming from the center area near F7 key, below the screen but not inside the screen. It also seems to match the CPU activity (actually non activity), although the sound disappear while scrolling. This noise is really noticable only when plugged. It's a lot lower on battery.

It is also stronger when the keyboard backlight is on and after a little search, it seems that it is not the first dell laptop to having that issue. Apparently the previous XPS 15 has it too and a few more.

Note that I use a french version of the laptop and the power comes into the adapter at 220V.

I am seriously considering returning the laptop as this is a real issue and dell was aware of the same problem on others models released prior to this one and obviously didn't do anything about it to solve this on the latest releases.

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cjpaul
1 Copper

RE: Dell Inspiron 15 7000 - Buzz/electrical noise (hard to describe) when connected to AC

Hi Mike,

Thanks for your response.  Is good to know that I'm not the only one encountering this issue.  I'm from Ireland so working from a 230v power supply.  

One other thing I noticed is that when I turn off my laptop I hear a buzzing from next to where the power supply is connected.  This only goes away when I disconnect the plug from the mains.  Does not make this noise when the laptop is running.  

Despite these 'noises' I am overall very pleased with my laptop as is whisper quiet most of the time other than the expected ramp up of the fans for CPU extensive tests.  So from that point of view it doesn't bother me too much but nonetheless would appreciate some feedback from Dell as to whether these 'noises' are expected or not.

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mikedo7
1 Copper

RE: Dell Inspiron 15 7000 - Buzz/electrical noise (hard to describe) when connected to AC

Yes, we are definitely not the only ones! Dell should be more concerned with that issue that has been going on for a while now.

I'm gonna run some more "tests" tomorrow and if I don't feel satisfied with all that, I'll just ship it back and buy a asus zenbook pro instead.

While you're mentioning  the fans noise, I have to say that the laptop is really quiet when not too busy BUT, when you start needing more cpu, sometimes even just a youtube video, the fans kick-in and it gets really loud, like there is no intermediate speed. this is all or nothing, the fans rpm doesn't speed up smoothly like on my current asus s200e.

Anyways, these inconveniences are not what I was expecting from a 1200€ latop.

RE: Dell Inspiron 15 7000 - Buzz/electrical noise (hard to describe) when connected to AC

(Given:  At least one SSD (Solid State Drive) system; meaning there are no moving parts within the main storage Drive.)

Since there is no Device Manager entry for the fan, it is not possible to disable it in order to check whether it is the source of the noise.  I have seen third-party fan utility programs, but I cannot recommend using one of those, like the one programmed by a guy in Italy as a project for his classes at university (that I used almost 5 yrs. ago), that is something you would need to consider for yourself.

Has anyone tried plugging in a headphone (ear buds) to see if the sound "disappears"? - Reasoning that it might be some sort of audio "feedback" being caused by a source of Radio Frequency (RF) interference inside the computer.  The most common source of interference I know of are small coils but, if these are inside the laptop they should be really, really tiny; and most of the electrical activity is rather "low key".

Possible sources of interference *might* be:  CPU cooling fan, CD/DVD drive motor, audio step-up transformers, or varying voltage between Sound-IN and Sound-OUT circuitry (again, feedback).  Remember in the good old days if you placed a microphone too close to a speaker, the two would interact with each other and a high-pitched "squeal" was [often] produced.

Good luck isolating the issue gentlemen.

sontanon
1 Copper

RE: Dell Inspiron 15 7000 - Buzz/electrical noise (hard to describe) when connected to AC

SOLVED: I had the exact same problem (buzzing noise under the F7 key). I noticed that it became really noticeable while using the camera or the microphone so I concluded that it was an audio problem. Uninstalling the Realtek driver under Device Manager solved everything. Hope this helps.