EarFun UBOOM® - Black

Step1: Power on your device
Step2: Once power on，the speaker should automatically begin flashing blue.
Step3: Go to the Bluetooth Manager of your smartphone
Step4: Turn Bluetooth on, then select EarFun speaker

Step1: Power on 2 speakers
Step2: Press the Bluetooth button of 2 speakers at the same time for at least 5s. Until you hear a reminder sound, which indicates a successful pairing between them. (the master speaker will come with a blue blink light again, and another is slavery speaker)
Step3: Press the Bluetooth button of the master speaker one more time, then connect it with your device.
After the above steps, these two speakers will be pairing successfully.

Option A:
Unpair the speakers from your Bluetooth-enabled device and delete the old connection on your device.
Option B:
You can press and hold “Volume +” and “Volume –” buttons simultaneously for 5s at least until the power-on button flashes in light pink or purple and the indicating sound comes up.

You may need to change the default audio output on your PC to "Bluetooth speaker".
Step 1. Close all media applications in your PC (such as Windows Media Player)
Step 2. Open 'Control Panel' > 'Sounds and Audio Devices' > 'Audio'
Step 3. Change the default output device to "Bluetooth speaker" in Sound playback

Yes it is possible but only after disabling the original device's Bluetooth or deleting its pairing record before pairing the new device.

No pin should be required. Restart your computer and try to re-pair.

It will take around 4 hrs at 5V/2A for a full charge.

Playtime varies according to volume level and audio content, at 50% volume, playtime is around 16 hours.

No.

Double check your cable and charger with another device. If the speaker has remained discharged a long time it may take a while to show it is recharging.

Yes.

It will automatically turn off after 30 minutes when no connection. But it won’t turn off when being charged or connected.

If the battery is empty, the device will shut down to storage mode. In storage mode, the LEDs are not active. Charge the device for a while and then turn it on to see the LED light.