Disclaimer: this information have been found on fedora forum and are here because they are valuable to me.

I have a cheap laptop always with me, a Dell Inspiron 15 (3551 if you are interested) and it comes preloaded with Ubuntu and a Dell repo preconfigured.

Installing Ubuntu Gnome, Fedora or Debian from scratch always resulted in a not working touchpad but now I solved the problem and I’m running Debian.

Switching to Debian fixed these issues:

1. Random unresponsive lockscreen
2. Ubuntu locked to 14.04 LTS without guaranteed updates from Dell

Drawbacks:

1. I could top 11 hours of computing without Wifi, now I can top 6 hours.
2. The touchpad stopped working
3. The integrated Bluetooth is not recognised by the kernel

The issue n° 2 is pretty much what locked me to use Ubuntu and what kept exploring Xorg and the world of xorg.cong files in an attempt to fix it.

the synaptic fix

1. Edit the default Grub file with editor /etc/default/grub. Append to GRUB_CMDLINE_LINUX the string i8042.nopnp, save and exit.
2. Edit the i2c-hid.conf file with editor /etc/modprobe.d/i2c-hid.conf and append the line blacklist i2c_hid
3. Edit /etc/modules, add the string synaptic_i2c, save and exit.
4. Run depmod with depmod -a
5. Update your system images with update-initramfs
6. Update Grub with update-grub
7. Reboot

the bluetooth fix

This work for the Atheros AR9565 chipset¹.

1. create a file in /etc/modprobe.d/, I called it ath9k_bluetooth_coexists.conf
2. copy this line inside the previous file options ath9k btcoex_enable=1, save and exit
3. run depmod -a
4. run update-initramfs
5. reboot

the external monitor fix

This fix activates the external screen with a little work required when connecting

1. i915.conf in /etc/modprobe/
2. Change the Xorg configuration for your screen to use modelines

troubleshooting

I found that when the external screen is not correctly workgin I can close the lid and reopen it to give it a second kick. Another action you can take is to swtich from tty7 to tty1 anc back with the combination Ctrl + Alt + F1 and Ctrl + Alt + F7.