I have an Asus T102HA which has an integrated Qualcomm Atheros QCA9377 WiFi+Bluetooth adapter. The Bluetooth suddenly stopped working this morning and as a result the wireless mouse no longer works (this is how I knew Bluetooth stopped as I was using the machine at the time).
I checked in Device Manager and the Bluetooth devices were greyed out though they were not disabled (had to enable 'Show hidden devices' in Device Manager to see the Bluetooth section in the device tree).
I proceeded to uninstall and reinstall the Atheros QCA9377 driver as available from the Asus website (https://www.asus.com/uk/support/Download/3/919/0/1/EKnJ4vWdmuN3xLti/45/). Upon reinstalling the driver Bluetooth is no longer listed anywhere in Device Manager.
I have run the "Scan for hardware changes" in Device Manager but this does not detect anything new.
It is as if the Bluetooth device no longer exists on the system. However, WiFi is working fine which would suggest that the device itself is presumably ok and still present.
The only possibly suspicious thing to note in Device Manager is a device under:
Universal Serial Bus controllers > Unknown USB Device (Device Descriptor Request Failed).
I have no USB devices connected to the system so it is unclear what this unknown USB device is above – perhaps it could be the Bluetooth adapter but I don't seem to be able to get that unknown device to find a driver update online.
The Windows 'Bluetooth Support Service' is running and can start/stop successfully – it is also set to Automatic startup.
Airplane mode is not enabled and toggling it on/off has no effect on the Bluetooth situation, though it does turn WiFi on/off as it should.
I am out of options that I know of to troubleshoot this as Bluetooth isn't showing up no matter what I do.
How can I troubleshoot further and get the Bluetooth adapter reinstalled properly?
Best Answer
After reading this, here's roughly what I did:
Uninstalled the Unknown USB device from Windows Device Manager (it was stating "Device descriptor request failed");
Went to Asus official drivers website, downloaded the latest bluetooth drivers for my motherboard and installed them;
Shutdown the computer, and "unplugged" the power for more than 30 seconds;
After powering it back on, windows had Bluetooth working again.
Keep in mind that I had reinstalled the Bluetooth drivers multiple times, always restarting the computer in between, and nothing changed. Only after unplugging the power did I actually manage to solve this issue.
This tells me that the underlying issue was hardware related, and depriving the motherboard from power reset the Bluetooth hardware to a good state.