As no one has posted an answer yet, I’ll post a few solutions to try and it will hopefully inspire others with more experience to post answers.

See what others have tried

From Unix & Linux site there is this Q&A: How to pair Bose Soundlink Bluetooth using pulseaudio in Linux Mint Debian:

sudo nano /etc/bluetooth/audio.conf # Insert lines below & save
[General]

Disable=Socket
Enable=Media,Source,Sink,Gateway

Then the commands:

sudo service bluetooth restart
sudo pactl load-module module-bluetooth-discover
sudo pactl load-module module-switch-on-connect

Don’t try these steps as is, Read the entire answer!

Table of Contents

• See what others have tried
  • Answers in Ask Ubuntu
• Another method of gathering log info
  • journalctl sample log:
  • Turning bluetooth speakers on
• Bose Revolve Soundlink troubleshooting
  • Bluetooth Will Not Pair
  • Speaker isn’t in Bluetooth Mode
  • Bluetooth isn’t Turned on or Enabled on Your Device
  • The Device You are Trying to Connect to the Speaker to may be Out of Range
  • There is Something in Between Your Device and the Speaker
  • Multiple Paired Devices
  • There Have Been Eight Devices Connected to the Speaker
  • The Speaker’s Motherboard May be Faulty

Answers in Ask Ubuntu

Another answer worth checking out is: How to get Bose Soundlink Mini Bluetooth Working

Another method of gathering log info

With Ubuntu 16.04 and greater you can open a terminal and type journalctl --follow. Then perform various GUI actions such as bluetooth pairing and see system messages in real-time. This gives you a systemd alternative to dmesg.

Below is log output from journalctl --follow where:

• Bluethooth visibility was turned on
• Sony external speaker was set for pairing
• Attached Motorola phone which was previously paired to speaker was woken up to turn off the phone’s bluetooth

journalctl sample log:

$ journalctl --follow
-- Logs begin at Mon 2018-03-05 05:53:18 MST. --
Jul 07 09:49:05 alien dbus[762]: [system] Rejected send message, 2 matched rules; type="method_return", sender=":1.34" (uid=0 pid=1527 comm="/usr/lib/bluetooth/bluetoothd -E ") interface="(unset)" member="(unset)" error name="(unset)" requested_reply="0" destination=":1.63" (uid=1000 pid=2519 comm="/usr/lib/x86_64-linux-gnu/indicator-bluetooth/indi")
Jul 07 09:49:40 alien kernel: nouveau 0000:01:00.0: DRM: resuming kernel object tree...
Jul 07 09:49:41 alien kernel: nouveau 0000:01:00.0: DRM: resuming client object trees...
Jul 07 09:49:41 alien kernel: nouveau 0000:01:00.0: DRM: resuming display...
Jul 07 09:49:41 alien kernel: nouveau 0000:01:00.0: DRM: resuming console...
Jul 07 09:49:46 alien kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
Jul 07 09:49:46 alien kernel: ACPI: \_SB_.PCI0.PEG0.PEGP: failed to evaluate _DSM
Jul 07 09:49:46 alien kernel: ACPI Warning: \_SB_.PCI0.PEG0.PEGP._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20150930/nsarguments-95)
Jul 07 09:49:46 alien kernel: nouveau 0000:01:00.0: DRM: suspending console...
Jul 07 09:49:46 alien kernel: nouveau 0000:01:00.0: DRM: suspending display...
Jul 07 09:49:46 alien kernel: nouveau 0000:01:00.0: DRM: evicting buffers...
Jul 07 09:49:46 alien kernel: nouveau 0000:01:00.0: DRM: waiting for kernel channels to go idle...
Jul 07 09:49:46 alien kernel: nouveau 0000:01:00.0: DRM: suspending client object trees...
Jul 07 09:49:46 alien kernel: nouveau 0000:01:00.0: DRM: suspending kernel object tree...
Jul 07 09:51:20 alien kernel: usb 1-1.4.4: new high-speed USB device number 13 using xhci_hcd
Jul 07 09:51:20 alien kernel: usb 1-1.4.4: New USB device found, idVendor=22b8, idProduct=2ea4
Jul 07 09:51:20 alien kernel: usb 1-1.4.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Jul 07 09:51:20 alien kernel: usb 1-1.4.4: Product: Moto E (4)
Jul 07 09:51:20 alien kernel: usb 1-1.4.4: Manufacturer: motorola
Jul 07 09:51:20 alien kernel: usb 1-1.4.4: SerialNumber: ZY224VD3MX
Jul 07 09:51:20 alien mtp-probe[17678]: checking bus 1, device 13: "/sys/devices/pci0000:00/0000:00:14.0/usb1/1-1/1-1.4/1-1.4.4"
Jul 07 09:51:20 alien mtp-probe[17678]: bus: 1, device: 13 was not an MTP device
Jul 07 09:51:21 alien kernel: usb 1-1.1: usbfs: interface 0 claimed by usblp while 'brscan-skey-0.2' sets config #1

There might be other messages the system is generating at the same time that you might to ignore.

Turning bluetooth speakers on

Using the systray GUI, when clicking the Off to turn it On this message appears in the terminal:

Jul 07 10:14:32 alien bluetoothd[1527]: Unable to get Headset Voice gateway SDP record: Host is down

Because the speakers have no microphone so the message is trivial.

Bose Revolve Soundlink troubleshooting

From here it suggests:

Bluetooth Will Not Pair

Your Bluetooth device will not pair to the speaker.

Speaker isn’t in Bluetooth Mode

Make sure your speaker is in Bluetooth mode by pressing the Bluetooth button on the speaker while it is on. When the speaker is ready to pair, the LED next to the Bluetooth button will flash blue, and, if the voice prompts are on, the speaker will say, “ready to pair”.

Bluetooth isn’t Turned on or Enabled on Your Device

Make sure the Bluetooth for your device is turned on or enabled and try to pair it again.

The Device You are Trying to Connect to the Speaker to may be Out of Range

The speaker’s wireless range is 30 feet. Make sure that the device you are trying to connect to the speaker is within that range and try to pair it again.

There is Something in Between Your Device and the Speaker

Make sure there isn’t anything between your device and the speaker, like bodies, walls, etc. and try to pair it again.

Multiple Paired Devices

Only one device can be connected to the speaker at a time. If there are two devices paired to the speaker, turn off the Bluetooth on the device you don’t want to be connected to the speaker and try to pair the device you do want to be connected to the speaker.

There Have Been Eight Devices Connected to the Speaker

The speaker can only store information about the last eight devices that were paired with it. To select your device, repeatedly press the Bluetooth button on the speaker until you hear the name of your device. If you don’t hear your device’s name, clear the speaker’s device memory. To clear the memory and connect your device, press and hold the Bluetooth button on the speaker until you hear a tone and, if voice prompts are enabled, you will also hear a voice prompt. Then the Bluetooth light will begin flashing blue and you can try to connect your device to the speaker again.

The Speaker’s Motherboard May be Faulty

First, factory reset the speaker by pressing and holding the power button while the speaker is on until the speaker asks you to select a language and there is a flashing blue light. Select a language and try to connect your device to the speaker again. If your device still won’t connect to the speaker, consider replacing the motherboards as a last resort.