BT700 not recognized on USB

[DodoEngineer]

Hello,

I just bought a new headset with a BT700 bluetooth adapter. However, this adapter is not working on any USB port but the one directly at the docking station. I've tried powered and unpowered USB hubs, five in total, but the BT700 isn't recognized on any USB hub. The red LED doesn't even flash, nothing.

I did update the BT700 to the latest firmware (v0.0.1122.4724) but no change. Still, the only USB port working is the one at the docking station.

I have multiple USB devices perfectly working on the various USB hubs, so they are not broken. Infact, even an older BT600 is working fine at my desk.

Any idea what's going on here and how to fix it? Or do I need to return the headset with a faulty BT700 adapter?

Thank you very much!

[M_Salman]

Hello @DodoEngineer, Welcome to the HP Poly Support Community.

Thank you for reaching out with your query regarding the Poly device.
 

I'm sorry to hear you're experiencing issues with the BT700. I completely understand how important it is to have your device functioning reliably, and I’d be glad to assist you in resolving this.
 

To begin, please follow the steps below to ensure the BT700 is correctly configured:
 

For macOS:
Go to System Preferences > Sound, then select Poly BT700 under both the Input and Output tabs.

For Windows:
Go to the Start menu > Control Panel > Sound > Playback tab. Select Poly BT700, set it as the Default Device, and click OK.
 

Additionally, if possible, please test the BT700 on a different Windows PC. This will help us determine whether the issue is specific to your current system.
 

Please let us know the outcome of these steps—I'm here to support you further if needed.
 

Take care and have an amazing day!

If you would like to thank us for our efforts to help you, go to the public post and give us a virtual high-five by clicking on "Yes" for the question "Was this reply helpful?" below my message, followed by clicking on the "Accept as solution" on my public post.

Regards,

Salman

[DodoEngineer]

Hello @M_Salman,

as I wrote, the BT700 does not get recognized on the USB ports. It does not show up in the system information tool or in dmesg. Just as if I never plugged it in. Except for this one USB port where it works like a charm.

This is not a problem of audio routing. When I plug it in to the one USB port where it works, it works like it should be. But I cannot use this port permanently as I need to plug a USB hub in there so I have enough USB ports for all the other devices like mouse, keyboard, printer, etc.

And with none of the USB hubs I have, the BT700 gets even recognized. But all my other USB devices work fine with these hubs.

Here is a recap of the situation:

1. BT700 works when directly plugged in to the docking station. -> No software issue with drivers or audio settings.

2. Available USB hubs work with all kinds of other USB devices. -> I conclude that they are all in good order.

3. BT700 works on none of the USB hubs. -> Why is that?

Any idea what's going on?

[DodoEngineer]

Solution

The BT700 required a USB charging port with higher current limits. It does not work on regular 500 mA USB ports.

Details

I tested with a Windows laptop and Windows can detect the BT700 fine on all available USB ports. However, Wireshark/USBpcap shows that the BT700 sometimes gets enumerated twice before it starts working. The Windows event viewer does not show any events other than new USB device detected.

Back on macOS, I noticed that dmesg shows an error when plugging the BT700 in:

AppleUSB20HubPort@: AppleUSBHostPort::setPortLocation: hub depth exceeded

Just randomly trying things, I noticed that the BT700 works on the charging port of powered USB hubs. This is reproducible. At the very same hub, regular USB ports don't work but charging ports with higher current limits work. Tested on the builtin USB hub in my monitor and a dedicated USB hub. Consequently, my trusty workhorse, a powered USB hub without charging ports, does not work.

On macOS that is. On Windows, the BT700 works on all available USB ports, regular or charging ports.

I have a similar behavior with an external mechanical hard drive which is bus-powered. It requires USB 3 ports with the higher current limits to work under macOS. But on Windows, it works even on old USB 2 ports (at lower speeds, of course) when the hub is powered sufficiently.

This should be transferred to HP/Poly R&D for further investigation. By the looks of it, this can be a problem with the inrush current which is known to be ignored by Windows.

[M_Salman]

@DodoEngineer, Welcome to the HP Support Community!

We're here to help you tackle bt700 issue Don't worry, we've got your back!

To get you the best assistance, we need to take this conversation to a private chat. We're inviting you to a private message to protect your privacy and ensure that any sensitive information remains confidential.
 

To access your private message, just click the little blue envelope icon on the upper right corner of your HP Community profile, next to your profile name. Alternatively, you can click on this link.

Private Messages - HP Support Community

We're looking forward to helping you resolve this issue!

Stay tuned, and thanks for your patience!

Regards,
Salman