Jump to content

DW1820a - the general troubleshooting thread


Recommended Posts

@Hervé I've tried my best to read up on this, and figure out how to fix my bluetooth issues, but I can't seem to succeed. Would like to get your guidance


Symptom: Bluetooth is recognised, and is able to discover devices, but is unable to connect to any device successfully (mouse, AirPods, non of them work)


Since its likely a USB discovery issues, I've attached the following materials, maybe you can point me in the right direction for this... I am using a very similar setup as your 7490 on 10.14.5 (except I'm on i5, without thunderbolt)

ioreg profile posted as well.


Thank you!












Link to comment
Share on other sites

  • Administrators

Funny that you copied all your add-on kexts to /L/E, except FakeSMC. Depending on your Clover settings, you could be trying to inject kexts that are already cached. So, copy FakeSMC to /L/E, repair permissions, rebuild your cache and set Clover kext injection to "Detect". Reboot and check Bluetooth again.


This being said, your setup is probably Ok: your Bluetooth SysInfo, things look identical to the info for my own card.



On my side AirDrop works perfectly with my other Hacks and so does HandOff with my iPhone. I had not even attempted to pair with any other Bluetooth device but on trying to connect to my JBL speaker, I too cannot establish a connection. I guess more work is required on that front. In all likelihood, Rehabman's kext need an update of firmware in which case you could try to extract the latest one as explained here. Device 0a5c:6412 is not mentioned in the list of tested devices but, nevertheless, it appears to be covered by a 4yr+ old firmware (BCM4350C5_003.006.007.0095.1703_v5799)...


Looking at the contents of BrcmFirmwareRepo, you'll see a list of firmware and that's where the latest version for the DW1820A should go. I'll try to update asap.

Link to comment
Share on other sites

  • Administrators

Ok, I downloaded the latest driver for DW1820A I could find on Dell's web site here (Win7 64bit for XPS 9350, dated May 2019). I extracted the firmware 1707 for our 0A5C:6412 DW1820A device:



All you need to do then is:

  1. copy the uncompressed .hex firmware file to the Resources folder of BrcmFirmwareRepo kext to supersede current version 1703 (=v7 c5799)
  2. update the key for device 0a5c_6412 in Info.plist file of BrcmPatchRAM2 kext
    • BrcmPatchRAM2_patch.jpg


After repairing permissions and rebuilding the cache, I can now connect to my JBL USB speaker without issues:

BT_PrefPane.jpg     JBL4_audio_output.jpg




This firmware version 1707 (which equates to v7 c5803) seems to be quite old (dated December 2015) but works Ok nevertheless. I'll try and lookup for a more recent firmware than that one.


Edit: reverted to uncompressed .hex firmware file.


  • Like 1
Link to comment
Share on other sites



You are absolutely amazing. Thanks to you and the community, we now have a fully working DW1820a, both wifi and BT together! you solved this issue in a matter of hours, which I couldn't even do over several weekends!


Look at this... 2 devices at once!!



My work on Dell 7490 is almost perfect... what a beauty it is. Thanks again!!



Link to comment
Share on other sites

I've been doing further testing on bluetooth and wifi for DW1820a. Here are my observations so far:

- Bluetooth connection stutters. When using bluetooth mouse, the cursor jumps on the screen. When using AirPods, the audio skips.

- When left idle, bluetooth devices will disconnect on their own

- Bluetooth is more stable when wifi is running on 2.4ghz, or turned off


Initial suspect is related to power management to the card, or some form of interference. On windows the card works perfectly, which means it is not an antenna problem. 


@Hervé do you observe the same as well?

Link to comment
Share on other sites

This topic is now closed to further replies.
  • Create New...