I reflashed eventually and did not have sound, so this is clearly a hardware problem. Since my phone was still under warranty, I sent it for repair. So closing this bug as invalid, if anybody has a similar problem please open a new bug with the information of his/her device.
** Changed in: pulseaudio (Ubuntu) Status: Confirmed => Invalid -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to pulseaudio in Ubuntu. https://bugs.launchpad.net/bugs/1654722 Title: Ubuntu Touch: No sound on speakers but OK on headset Status in pulseaudio package in Ubuntu: Invalid Bug description: Since a couple of days ago I have lost all sound on the speakers of the phone (no application plays any sound, no ringtones, notifications), but sounds can be heard normally with a headset. Sound configuration looks OK, and restarting does not help. I tried to remove .config/pulse completely and restart, but no progress. I attach the file ubuntu-phablet-stream-volumes.tdb which was there before removing the folder and restarting. BQ E5, OTA 14. ProblemType: Bug DistroRelease: Ubuntu 15.04 Package: pulseaudio 1:6.0-0ubuntu9.25 Uname: Linux 3.4.67 armv7l AlsaInfo: This script requires lspci. Please install it, and re-run this script. ApportVersion: 2.17.2-0ubuntu1.3touch1 Architecture: armhf AudioDevicesInUse: Error: [Errno 2] No such file or directory: 'fuser' CurrentDmesg: Error: command ['dmesg'] failed with exit code 1: dmesg: read kernel buffer failed: Operation not permitted Date: Sat Jan 7 09:30:00 2017 InstallationDate: Installed on 2016-11-18 (49 days ago) InstallationMedia: Ubuntu 15.04 - armhf (20161118-171123) SourcePackage: pulseaudio UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/1654722/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp