Hardware

- Intel(R) Core(TM) i5-8250U CPU @ 1.60GHz
- 2 x 4GB SODIMM DDR4 2400 MHz
- Intel Corporation Device 5917 (rev 07) (prog-if 00 [VGA controller]) / UHD Graphics 620 - Kernel driver in use: i915
- Intel Corporation Device 9d71 (rev 21) (prog-if 80) / Sunrise Point-LP HD Audio - Kernel driver in use: snd_hda_intel
- Realtek Semiconductor Co., Ltd. RTL8411B PCI Express Card Reader (rev 01) / Kernel driver in use: rtsx_pci
- Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 12) / Kernel driver in use: r8169
- Qualcomm Atheros QCA9377 802.11ac Wireless Network Adapter (rev 31) / Kernel driver in use: ath10k_pci

What you need

- Working Linux computer (no idea how it works on Windows)
- Internet connection via LAN
- Acer Aspire :-)

1. Getting Debian image

- go to https://www.debian.org/distrib
- grab "64-bit PC netinst iso" (even if its name contains "amd" it works for i#86 too)

2. Create bootable USB stick using Linux

- cp debian.iso /dev/sdX; sync

Where "debian.iso" is the name of the downloaded image and "X" is the character identifying your USB-device (most likely "b")

3. Preparing Acer Aspire for installation

- switch on and press F2 to enter BIOS
- enable boot menu F12
- set secure boot to legacy
- disable network boot
- save changes and exit BIOS

4. Start installation

- put in USB stick
- switch on
- press F12
- select USB
- follow the instructions and make your choices
(my additional choice: xfce)

5. Install missing firmware

- open a text editor and update /etc/apt/sources.list (add contrib non-free and backports)

As an example, my sources.list:

deb http://ftp.de.debian.org/debian/ stretch main contrib non-free
deb-src http://ftp.de.debian.org/debian/ stretch main contrib non-free

deb http://security.debian.org/debian-security stretch/updates main contrib non-free
deb-src http://security.debian.org/debian-security stretch/updates main contrib non-free

# stretch-updates, previously known as 'volatile'
deb http://ftp.de.debian.org/debian/ stretch-updates main contrib non-free
deb-src http://ftp.de.debian.org/debian/ stretch-updates main contrib non-free

# stretch-backports
deb http://ftp.de.debian.org/debian/ stretch-backports main contrib non-free
deb-src http://ftp.de.debian.org/debian/ stretch-backports main contrib non-free

Depending on your location you may not want to use server in Germany.
Please enter a server name near to you.

- apt-get update
- apt-get install firmware-atheros
- apt-get install firmware-realtek
- apt-get install firmware-misc-nonfree
- apt-get install accountsservice (to avoid (harmless) lightdm Error getting user list...)

6. Grant access for xfce4-sensors

- chmod u+s /usr/sbin/hddtemp

7. Enable touchpad tapping and scrolling

- Add 2 lines (the options, see below) to /usr/share/X11/xorg.conf.d/40-libinput.conf

Section "InputClass"
Identifier "libinput touchpad catchall"
MatchIsTouchpad "on"
MatchDevicePath "/dev/input/event*"
Driver "libinput"
Option "Tapping" "on"
Option "NaturalScrolling" "true"
EndSection

8. Restart and enjoy :-)

Functionality

Suspend to RAM (standby): ok
Suspend to DISK (hibernate): does not work!

LAN: ok
WLAN: ok (after installing firmware)
Mic intern: not tested
Mic extern: not tested
Audio intern: ok
Audio extern: ok
Touchpad: ok (tapping/scrolling enabled after adding options)
Webcam: ok
Cardreader: ok
HDMI: ok
Laptop special keys: ok (except "flight mode")
Bluetooth: ok, but...

Bluetooth issue in my system:
- pairing and connecting to headset was ok but no sound
see how-to-fix-no-audio-with-bluetooth
and/or A2DP_not_working_with_PulseAudio

I have configured my headset as "High Fidelity Playback (A2DP Sink)". Now the sound works. (But most likely not the Mic)

Remark

A piece of paper was delivered with the Laptop, saying:

"Notice regarding ENERGY STAR Specifications for Linux OS
Since the Linux OS does not support advanced power management utility
capable of entering a low power state after a period of inactivity, this product
may not meet the ENERGY STAR Program Requirements for Computers"