SkidMan

My Feedback: (17)

This is the case of a JR DS285MG HV servo working with a Turnigy servo tester and not with several Spektrum receivers.

It is installed as an aileron servo in a DLG glider and had been working previously. After replacing its twin on the other side, and previously working, when I plugged everything back together for a little flying the older servo would not work, and the newly installed one did. Reversing the left and right servos did not change anything - the new servo worked and the older one did not no matter what channels I plugged them into.

I attached the older servo to a Turnigy servo tester and it works perfectly. It will center, work under manual control, and auto cycling. It operates perfectly.

But, as you can imagine, when I plug it back into the receiver the older servo will not operate on any channel and its newer twin will work just fine.

I then tried different receivers with different resolutions with exactly the same results.

Receivers used:

• AR6255 - Original receiver that it has flow with
• AR6200
• AR6100e

If the servo just did not work that would be one thing. But since it works with the servo tester I'm interested to see if there might be some other issue.

Thanks,
Paul

mongo

My Feedback: (15)

check the condition of the pins/sockets in the servo connector.
bet they have worn just a bit and are not making good contact on the rx, but the tester connections are less worn or a slightly tighter fit.

Truckracer

My Feedback: (19)

Two things come to mind. First, what is the operating voltage in the airplane compared to the servo tester. Second, perhaps the pulse output voltage on the servo tester is different than what the receivers' decoder provides. You can check the first point but would need a scope to check the second one. If the particular servo has become sensitive to pulse voltage, it might work on the tester and not the receivers.

Have you called Horizon service and asked them about the problem?

SkidMan

My Feedback: (17)

Mongo - I replaced the connector without any improvement

Truckracer - I used the same batteries on the servo tester and the receivers, both LiPo and LiFe. It would be interesting to check the pulse voltages. I tried the different receivers to try to see if 11ms vs 22ms made a difference. It didn't. I will try a lower voltage battery on the tester, like a 4-cell NiCd, to check the effect of a low pulse voltage.

Thanks for your suggestions.

Paul

Rodney

It has to be a connector or wiring problem. Double check to see if there is not a connector or extension or something used only when the servo that is NOT working is hooked up.

SkidMan

My Feedback: (17)

Rodney - I am plugging the servo directly into the different receivers and the tester.

chuckk2

The servo may be "loading" either the control signal or have an odd fault.
In any case, since the new servo works properly using the same connections,
it sounds like new servo time.
I had a JR821 servo that acted a bit wonky. (full speed in one direction, very slow in the other.)
Further, it was causing problems with another servo.
The servo tester may put out a stronger (higher pulse voltage) than the RX.
Unfortunately, I'm in Georgia, and a bit of distance from where you are, or I'd offer to
bench test the servo with lab equipment. (Digital Scope and pulse generator, along with a servo tester, etc.)