If you're still out there. Try this using a Terminal="Applications->Accessories->Terminal"
echo "options snd-hda-intel model=hp-m4" | sudo tee -a /etc/modprobe.d/alsa-base.conf
I'm not sure what to do here. I see you've instituted the fix for the mic, but apparently that doesn't help with headphones. Try removing that line from alsa-base.conf and replacing with one of these models:
One at a time please until something works. Ideapad and thinkpad are where I would start.
laptop Basic Laptop config (default)
hp-laptop HP laptops, e g G60
asus Asus K52JU, Lenovo G560
dell-laptop Dell laptops
dell-vostro Dell Vostro
olpc-xo-1_5 OLPC XO 1.5
ideapad Lenovo IdeaPad U150
thinkpad Lenovo Thinkpad
Syntax: options snd-hda-intel model=xxxx
Try this using a Terminal="Applications->Accessories->Terminal"
echo "options snd-hda-intel model=asus-mode3" | sudo tee -a /etc/modprobe.d/alsa-base.conf