Description:
There are two types of buzzing, both coming from the cpu / ram area
(near the letter Q of the keyboard).
To be more precise, I describe the two hums separately (buzzing A and buzzing 
.
I state that:
The
PC and the power supply have been kept as a relic and in the six
months' time they did NOT suffer shock, vibrations, exposure to cold
temperatures, infiltration of liquids, etc.
I've
found the buzzers for about two months, I do not know if it's a factory
defect, it's in fact that from March in a house near a river (I can try
it) and I could hear the buzzes when I brought the pc in
areas with more ordinary environmental noise levels (both normal homes
in neighborhoods with car traffic and in the library / study areas).
Before
"disturbing" with the email I had to make some backups because I was
worried about a sudden technical problem and I also searched (official
websites acer or not) to understand if it was something solvable, of
little consequence, or such as to request information from technical assistance. In
my possible I have also carried out many tests / checks which are
reported in detail with the hope of "helping you" to make a picture of
the situation.
Buzzing A:
It is well audible while sitting in front of the PC. I
have also attached audio recordings to give an idea of the extent of
the phenomenon that resembles a "cicada" or "chirping" depending on the
type of operation that is performed.
It manifests as "cicada" when you make a simple zoom in / out of a photo or scroll through multiple photos with the mouse wheel.
It
manifests as "chirping" for example during the simple conversion of one
or more photos from one file format to another (with any percentage of
compression / quality).
These operations were performed with Nikon's original software (both view nx-i and capture nx-d). Initially I thought that the buzz A was caused only by these software but unfortunately it is not so. The
chirping is audible in the initial phase of processing / conversion and
then decreases in the final phase until it is confused with the fan at
about medium speed and stopped.
I
am very perplexed because a 13-year-old desktop computer was doing the
same operation much more silently and above all with lesser processor
utilization.
Precise
that the buzzing A is much less audible almost impossible when the pc
is powered only by the battery also changing the energy mode from the
windows taskbar.
Buzzing B:
Increases
the intensity in the startup phase of the PC, in idle, when the CPU is
under load, when I make movements with touchpad and mouse (especially
scroll wheel and click scroll) and in particular when there are videos
playing or any animation on screen.
In short, it manifests itself with any software including windows at any frequency and percentage of use of the CPU. The
buzz is constant unlike the buzz A and is similar to something that is
"frying", is audible already at a distance of about 15-20 cm from the
pc.
If I do not use a mouse and touchpad, the buzzing is still present, however, it is much less audible. I
have also noticed that this buzz has a periodicity corresponding to the
cpu usage graph in activity management and speed variation when
changing the update rate of the CPU usage graph.
Noise decreases if the PC is powered only by battery.
*
The buzz does not seem to come from the speakers and so far I have not
perceived disturbances with different types of earphones and brand.
*
Case instead of popping from the speakers is when I start a video
without volume (volume of the video player activated but general volume
of the realtek sound card turned off).
Between
official and non-official forums and communities, some PC owners with
similar or similar problems say that it is a quality defect of
insulation of the windings / capacitors on the motherboard / gpu / cpu
or even of current / voltage regulators, psu, of the GPU, etc.
Although
I am passionate about computers, I do not have detailed technical
knowledge about it, so I simply limit myself to reporting what I have
read.
As
mentioned at the beginning of the letter, I have also done many tests /
checks and most of what I remember brings it here (not in chronological
order) hoping to "help you" to make a picture of the situation:
- visual / auditory control of power supply and of the supplied cables
- PC / operating temperature control
- visual control of usb ports, jack, sd
- power supply connected to the mains without load (pc)
- power supply connected to the mains but with pc (off)
- test with different electrical sockets and in different buildings
- try with other mice
- reset mouse driver and touchpad
- control / reset of advanced energy management (advanced windows control panel)
- deactivation of audio outputs (no audible whistles with speakers / earphones / headphones)
- selective USB suspension control
- control in "device management"
- audio / video driver update *
- deactivation of the audio / video card *
- audio / video driver reset *
- battery charge / discharge check
- pc suspension
- hibernation pc
- control with "acer care center"
- deactivation / reactivation of the monitor
- monitor brightness
- on / off back-lighting keyboard
- USB 3.0 "acer quick access" charging function control
- hdmi control and driver
- bios acer updates
- formatting, reinstallation, updates (windows)
* (intel) e (nvidia)
-------------------------------------------------- ------------------------------------------------------------------------------
I have also attached image files (screenshots) of my pc and a video of a user who has the same buzzing B.
I
am obviously very worried because i need the laptop to study engineering,
manage photos / video memories of all the family, maybe even to work in
the future.
ps: i bought the notebook 6 months from a famous physical store.
pps: attached video has recorded by other person with different pc (it's just someone who has similar buzzing like me,
the microphone in the video makes the buzzing more perceptible) 
https://www.youtube.com/watch?v=eRUsG7h46sM
Sorry for bad english but i didn't have time to write directly in english so i used google translate.
