TGYIA6B will not communicate with servos

[SSgt Duramax]

Alright, I am trying to get my F86 in the air. I was running out of receivers and servos, so I ordered a new batch of each. The servos I bought were the el cheapo 9g servos I usually run. They seem to have a failure rate of about 10%. That is about every 10 servos I get, about one of them dies. I am using turnigy/flysky stuff, and I ordered a new batch of receivers.

I have been chasing my tail on this, here is what I have came up with:

1. All servos work when connected to a servo tester.

2. All servos work when connected to one of my old receivers (although one jitters, I replaced it and it doesn't go away).

3. My old batch of servos works with the new receiver.

4. I have tried rebinding and resetting the model. I shouldn't have needed to because it was new, but it was worth a shot.

5. I thought it may have been a faulty y cable for the ailerons, as only one aileron will work with the new receiver. No dice. I disconnected it to see if there was a short, that did not work.

6. I am currently running one of these IA6B receivers in my model A with no issues. I am unsure of if there are any of my new batch of servos on there.

7. I tried powering it off a known working ESC without issues to rule out the BEC, and there was no change in behavior.


So I have a question as to what could have gone wrong, and I can't find an instruction manual for the "B" version of these. It seems paying a dollar more for a receiver with more gizmos on it bit me in the butt.

Question 1: What is it about this new batch of servos that would cause it not to communicate with the receiver? Obviously on the outside they look exactly the same, and there is no visual difference, but something HAS to be different, right?

Question 2: Is there some kind of setting with the receiver/transmitter I am missing? Did I accidentally enable something on my model A that worked? I noticed there is I Bus and some other plug ins on it, and a light for updating it, but I am unsure of what is going on.

So these are functional servos, which work, and I tested them before I glued them in the plane, but this drives me bonkers. Hopefully it is an easy fix I am just looking over. Thanks in advance. I'll attach pics in a minute.

 

[SSgt Duramax]

The one on the left is the B version, those are the "new" receivers.

This is an otherwise functional servo that works with the "old" receiver, but not the new one.

This is what i believe to be a "new" batch servo which seems to be working fine with one of said receivers in my model A

This is said receiver which controls my model a.

My short term fix will be to stick one of those receivers in the micro kadet, and use that receiver in the jet. I dont want to raise a stink and start returning stuff until i figure out the problem isnt on my end.

 

[SSgt Duramax]

I tossed one in the micro kadet. It worked fine with those 5G servos. I'll probably toss the other one in my zero, as it has the same servos.

The servos are still ticking in the jet, but it should work well enough. It is the "old" servos that are ticking too.

 

[Tench745]

You walked us very nicely through the troubleshooting steps you've done. Well done, and that will be helpful in eventually figuring out the solution.
Unfortunately, you neglected to explain in detail the problem you are having.
I can deduce from your post that some servos aren't working in a model using the ia6b rx. What exactly are or aren't they doing?

 

[SSgt Duramax]

You walked us very nicely through the troubleshooting steps you've done. Well done, and that will be helpful in eventually figuring out the solution.
Unfortunately, you neglected to explain in detail the problem you are having.
I can deduce from your post that some servos aren't working in a model using the ia6b rx. What exactly are or aren't they doing?

I thought that was in the title?


They arent doing anything. They may as well not be hooked up. It is not communicating with the servos, or the servos "dont understand the signal."

It is only this one batch of servos, which are the exact same ones I have ordered from the exact same seller.

So i figure that the pwm signal is either not getting sent by the receiver or not being received by the servo. The problem is specific to the servo as i can move a servo that worked on another channel to the inoperable channel and it works. Which makes be rule out the receiver in a sense.

My hunch is there was a change in the manufacturing of the servos where the pwm signal from the "b" receiver isnt read, but the servo can pick up the signal from the servo tester and my other "old" receiver.

 

[Tench745]

It was in the title, but generally one will go into a little more detail in the post and describe the exact behavior.
For example, this part confuses me:

The problem is specific to the servo as i can move a servo that worked on another channel to the inoperable channel and it works. Which makes be rule out the receiver in a sense.

Saying that you have some channels that work and others that don't implies that only some channels on the ia6b aren't working correctly. But your title says they won't communicate at all?

 

[SSgt Duramax]

It was in the title, but generally one will go into a little more detail in the post and describe the exact behavior.
For example, this part confuses me:
Saying that you have some channels that work and others that don't implies that only some channels on the ia6b aren't working correctly. But your title says they won't communicate at all?

There are servos that work, and servos that dont.

For example, if the servo plugged into the rudder channel isn't working, and the one plugged into the aileron channel is working, I switch them, and the problem follows the servos, the rudder channel now works, and the aileron doesnt.

 

[Tench745]

Okay, I follow now. I don't know why that was so hard for me to understand.
The ia6b receiver works fine with the old servos but one of your new servos plugged into that same channel does nothing.
And the new servos work on the older ia6 receivers. That is very odd.
If the new servos didn't work with anything I would wonder if the plugs got soldered on wrong or something, but because they work I don't know...
Servos just listen to a PWM (pulse-width-modulation) signal from the receiver. My only guess is that the new RX might have a different frequency for its PWM signal than the old one. I always assumed that was pretty standard across the industry though.

My only other thought is maybe something is weird in the receiver firmware.
Hopefully someone with a little more knowledge in this area will chime in here soon.

 

[Tench745]

I did some quick googling and one other possibility that came up is that the pins in the new receiver are a slightly smaller size or the sockets on the new servos are slightly larger so they don't make good contact in a specific pairing. It's admittedly a long shot.

 

[SSgt Duramax]

So I went through this whole batch of servos I got, and about 12 of them jittered real bad on my "original" receiver. Some of them were silent (about 7). The ones which did not jitter and seemed to work on the "original receiver" also worked just fine on my "B" receiver.

So the problem was servo specific. I was worried that there was some setting that was messed up on something, and it just ended up being janky servos. The guy is going to give me my money back. I guess I'll just strip them and save the gears in case I strip a gear in another servo or something.

I want the hours I spent back testing everything and confirming which servos were bad. Time is the price you pay for being cheap sometimes.