Bluetooth Interference RT-AC3100 - new hardware solves it

[Peter Near]

I've been pulling my hair out for several days troubleshooting a bluetooth interference issue. I've had this router working wonderfully for a year, and the bluetooth issues in my home office just started in the last 2-3 weeks.

Long story short, I've isolated it to the 2.4GHz radio on my RT-AC3100 router. Turn off the radio in pro settings, my bluetooth devices start to work properly again.

Didn't get too far with first-level ASUS support beyond the basic "change the channel, move the router", so I went to the store to get a new router for comparison. Same model number, but hardware revision on my existing is A2 and new router is revision A6. With the same config and same wireless channel auto-selected, my bluetooth devices are working normally again with new hardware.

My questions for the group:
- Any significant differences in hardware revisions or is that just coincidental?
- How is the ASUS RMA process in Canada/Toronto? Will I be without a router for more than my 30-day return period on the new one? On principle I'd like to get it replaced by ASUS but I need it for work so will eat the cost if needed.
- Anything I might have missed? Will go over the detail of what I've tried below.

Troubleshooting so far:
- Enable/disable all bluetooth devices in the house
- Ensure all bluetooth devices are updated and fresh batteries
- Enable/disable new EcoBee smart thermostat (timing of issue coincidental with new thermostat)
- Change channel on primary router
- Reduce router Tx power
- Toggle all options for Bluetooth coexistence
- Update Merlin 382 firmware
- Reset to factory defaults
- Revert to 380 Merlin firmware
- Revert to ASUS firmware
- Switch nearby wifi devices to 5GHz (MacBook, iPhone)
- Toggle 2.4GHz radio in Professional tab (works, but I need 2.4GHz for my home)
- Swap router with new hardware (works)

Thanks in advance!
-Pete

 

[maxbraketorque]

Did you by chance try the latest firmware (384.10007) for both the A2 and A6 version? One of the stated highlights is that USB speeds are greatly improved. This would seem to suggest that they have found a way to improve coexistence between USB 3 and the 2.4 GHz band. I'm wondering if when you tried the A6 that you tested with 384.10007 while for the A2 version, you tried some earlier firmware.

 

[RMerlin]

How is the ASUS RMA process in Canada/Toronto?

Asus's service center is located in Ontario (I forgot which town, I've handled a few RMAs with them over the years for work). Last time I sent an RT-N12, it took about 2-3 weeks if I remember correctly.

Newer firmware versions have an option to improve Bluetooth co-existence. The root issue is that Bluetooth also uses the 2.4 GHz band (hence the recommendation to try a different channel). Make sure you enable that co-existence option.

 

[Peter Near]

@Max thanks for the suggestion, yes I've tried the latest firmware on both A2 and A6. A2 still exhibits the bluetooth interference, A6 does not.

@RMerlin thanks for the suggestion and for all the work you put into the firmware and community! Yes, I've tried all combinations of Bluetooth coexistence and that didn't improve the interference on the older A2 router.

I'm going to use the A6 router for a few more days until level 2 support calls me back, and assuming it continues to work well I will ask them to process an exchange/return.

-Pete

 

[Peter Near]

Followup for anyone who comes across this thread later via a search.

- ASUS RMA in Toronto was fairly painless. I was able to drop off the router at the service depot in Markham. If they had one in stock they would have swapped it for me right there, but they had to order one in. Replacement unit arrived at my home in 6 calendar days.

- The refurb unit was another Hardware Revision A2, and after a few hours of use I don't appear to have the bluetooth issue.

My conclusion is that there was indeed a hardware issue causing my bluetooth interference.

@RMerlin When moving config from my "new" A6 router to my "new to me" A2 refurb I used the settings backup for the first time in your 382 firmware. OpenVPN client didn't connect when I restored the settings to my refurb, and it looks like the Certificate Authority info didn't port over in the backup/restore. I had already wiped the A6 router at this point so I can't verify for you but I am 90% sure that the CA was in there and the OpenVPN client was working before the backup. Could be a bug.

 

[FreshJR]

Does Bluetooth cover the entire 0-11 channel wifi range?

My router interferes with my DS4 controller, or maybe the controller is glitching at certain times for another reason, and I'd like to know up I should be in the lower or upper part of the range.

 

[RMerlin]

Followup for anyone who comes across this thread later via a search.

- ASUS RMA in Toronto was fairly painless. I was able to drop off the router at the service depot in Markham. If they had one in stock they would have swapped it for me right there, but they had to order one in. Replacement unit arrived at my home in 6 calendar days.

- The refurb unit was another Hardware Revision A2, and after a few hours of use I don't appear to have the bluetooth issue.

My conclusion is that there was indeed a hardware issue causing my bluetooth interference.

@RMerlin When moving config from my "new" A6 router to my "new to me" A2 refurb I used the settings backup for the first time in your 382 firmware. OpenVPN client didn't connect when I restored the settings to my refurb, and it looks like the Certificate Authority info didn't port over in the backup/restore. I had already wiped the A6 router at this point so I can't verify for you but I am 90% sure that the CA was in there and the OpenVPN client was working before the backup. Could be a bug.

OpenVPN keys and certificates are no longer stored in nvram due to lack of space, therefore a settings backup will not contain these. You need a JFFS backup.