Receivers won't connect, register, or bind anymore

[getsuyoubi]

I had both my radio (X20S) and all my receivers on FW version 2.1.8 (coincidentally the same number) for about two years, but just about a week ago two of them would not connect anymore. I tried to register and rebind them - no luck, while at least two others still worked as they should. I sent one of the offending receivers to Aloft, and it worked perfectly fine. After updating my radio, the other receiver also works, and I updated all my receivers OTA to version 2.1.14. I expect that the one that I had sent to Aloft will also work now.
This puzzles me a lot, because it does not seem to make any sense to me that a FW combination that worked for two years all of a sudden does not work anymore - but only on two of my receivers.I contacted FrSky NA about this, but the response was not very helpful. Jarron at Aloft was very helpful, but in the end he was as puzzled about this as me, and he suggested that I start a new thread here.
Does anyone have any idea, or did anybody experience anything similar?

Thank you!

 

[Wayne]

Got me stumped as well.

 

[getsuyoubi]

I just tried the SR8 again - and again it won't connect, register, or bind! So I'm back to where I was a week ago. It seems the firmware update was just a red herring. I've contacted the FrSky service center again, and I will definitely send them my radio and the offending receivers.

 

[Wayne]

Sounds like a good plan. Please let us know what they report, can help future folks that have this issue.

 

[getsuyoubi]

Yesterday I tried to change the pin assignment on an Archer R8Pro, setting pin 1 to channel 9. I set that in the receiver menu on the radio, went successfully through the binding process, but pin 1 still shows no signal. In the output menu on the radio channel 9 behaves as it should.
This is a redundant receiver, connected via SBus to the primary one. So far I never used any channel outputs on this redundant RX, so pin 1 was never assigned to any channel before.
I hope you don't mind me posting all these issues here. It's basically for me keep track of what's going on, and I still haven't given up hope that someone has an idea what's going on.
The radio will be sent to FrSkyNA as soon as the SR6 arrives from Aloft, which is supposed to happen on Wednesday.

 

[getsuyoubi]

This is so weird. My radio and the three receivers arrived at the FrSky service center - and everything works! They were able to register and bind all three receivers, and will ship the radio back tomorrow because they do not see any issues.
I had tried to do this multiple times in two different locations (in the house and in the garage), with two different RX power supplies (a fully charged 6.6 volts LiFe battery, and a BEC powered by a 3s LiPo), without success. The only difference I can think of now is the TX battery, which I did not send with the radio. It's charged to 7.5 volts, which should certainly be enough to register and bind receivers.
I'm at a complete loss now. Even if everything works now it will take quite a while to get that warm and fuzzy feeling back...

 

[Wayne]

Not sure where you are located, if you are nearby please consider stopping by and we can run through some binding with you. Could be very helpful.

 

[getsuyoubi]

Sorry, I'm in NY. Would love to stop by, but that's not gonna happen...
I agree that at this point the problem seems to be between the ears, but I don't see what I might be doing wrong

 

[gnichola]

Maybe you could take a video of yourself trying to register/bind. I have seen here many times, when the written word misses some small but key detail.

 

[getsuyoubi]

I'm indeed planning to do that. Thanks!

 

[Landru]

I had both my radio (X20S) and all my receivers on FW version 2.1.8 (coincidentally the same number) for about two years, but just about a week ago two of them would not connect anymore.

Just stumbled on this conversation. What struck me was that the problem initially manifested not as a register or bind problem but as a failure to connect of a previously registered and bound receiver.

By no means am I sure of what's going on here. That said, I have myself encountered several failures of connection with a previously registered and bound ACCeSS receiver. So have other pilots. In some cases, the failure occurred suddenly in flight, causing the loss of a model. It strikes me that the same issue may be at play here. The problem was discussed at length on RCG over the course of several years: https://www.rcgroups.com/forums/sho...-ACCST-was-FrSky-R9-27-second-loss-of-control

The discussion above ended last year shortly after FrSky released firmware version 2.1.14, which was claimed to solve the problem. Based on incident reports and my own testing, I'm not so sure. Regardless, receivers running version 2.1.8 are known to be vulnerable to the problem.


Beyond the possibility that you've run into the 'NFL' problem above, I think power sources for the receiver and transmitter are worth considering. I say that because a number of us who use ELRS receivers have found that some units are only partially functional when powered by a NiMH battery pack of appropriate voltage. To my knowledge, the weirdness is not understood. One possible explanation is that the NiMH packs suffer from very brief voltage fluctuations that interrupt normal functioning of the affected receiver. Given that possibility -- and numerous other reliable reports of brownout issues with NiMH packs -- I avoid them altogether.

 

[jure]

I had a similar problem , no longer binding Rx , which was kindly solved by Jarron , by flashing the Rx to UNI firmware.

 

[getsuyoubi]

Hi Andrew,

Thanks for your valuable insight. The odd thing is that my receivers show this issue permanently, while the 'NFL' problem was likely just a momentary issue that did not permanently 'damage' the link. All receivers are on 2.1.14 anyway, so that did not make a difference either. I tried at least one of them by powering it through a BEC driven by a 2s LiPo, and it did not connect or bind either.
The only common 'ingredient' seems to be the radio. I had updated ETHOS from 1.4.15 to 1.4.17 a few days earlier, but that should not affect the RF section anyway. The radio worked with all three receivers at the FrSky service center, and there was nothing done to it there besides just registering and binding the receivers. I should get it back on Wednesday, and I will post a video here should I still have issues.

 

[getsuyoubi]

I had a similar problem , no longer binding Rx , which was kindly solved by Jarron , by flashing the Rx to UNI firmware.

These are ACCESS receivers on the latest firmware, not ACCST.

 

[Landru]

The odd thing is that my receivers show this issue permanently, while the 'NFL' problem was likely just a momentary issue...

Yes, that's a big difference. There were no reports of the NFL problem persisting after a transmitter and receiver reboot.

Reading through your previous posts, I understand that you encountered the problem with some of your receivers but not all.

Did I get that right? If so, it would suggest a factor specific to the affected receivers, not a general problem in the transmitter. Still, I suppose a receiver-specific problem might exist on the transmitter side. Along possibly similar lines, nobody provided proof of how the conditions that caused the NFL problem could come about in real world use. The most we know is that it supposedly depends on "abnormal conditions in the S.Port link".

I'm curious to know how you make out when the transmitter is back in your hands.

 

[getsuyoubi]

The most we know is that it supposedly depends on "abnormal conditions in the S.Port link".

There are no telemetry sensors connected to any of the receivers, so anything related to S,Port can likely be ruled out in my case..
I'm struggling to find any type of pattern in my observations, but there does not seem to be any. The problem occurs in two different locations (house vs garage), and with two different power sources (LiFe vs BEC). I successfully updated 5 or 6 receivers OTA from 2.1.8 to 2.1.14, while the three offending receivers don't connect, register, or bind. Then there is a 4th receiver (R8Pro) that does not seem to take pin assignments. I used that one as a secondary receiver for redundancy via SBus for two years, with no channels assigned to the pins, and wanted to use it not to control the position lights on a scale helicopter as the mechanics going into a fuselage. The radio shows channel 9 on pin 1, but whatever i connect to pin 1 does not do anything.

 

[Landru]

Those are a puzzling set of symptoms. Well, they are to me anyway.

Do you happen to have another ACCeSS transmitter to test with?

Regarding S.Port, my understanding is that the "abnormal conditions" that are believed to cause NFL can occur without any external sensors attached to a receiver. Certainly, NFL have been documented with no external sensors involved. Exactly what those abnormal conditions are and what causes them to occur has never been revealed that I'm aware. It seems possible to me that the exact mechanism is unknown. I don't mean to harp on this angle, though. It's possible what you've encountered has no connection whatever to NFL.

 

[getsuyoubi]

Unfortunately I'm the only one at the field using ACCeSS. There are a few using Radiomaster, but as far as I know those radios don't "speak" ACCeSS

 

[getsuyoubi]

At the FrSky service center they created a new test model in the radio and successfully registered and bound the three receivers I sent them to it.
When I get my equipment back, all I have to do is bind the receivers to the actual models that I want to use them on - correct? No need to first reset them at the test model?
I am now questioning everything that I thought I knew and that I'm doing, hence my question.

 

[Landru]

all I have to do is bind the receivers to the actual models that I want to use them on - correct?

Yes, that's correct to my knowledge.

Before you start, in your existing models, I think you should remove the listing for any receiver that was previously bound.