A member in our small RC group had the Internal XJT Transmitter in his Taranis-X9D, partially fail while flying.
We did a very disciplined trouble-shooting process that pointed us to the problem being with the Internal XJT transmitter module failing.
Working with Wayne at Aloft Hobbies, we did a lot of test flying, trying different external XJT and DJT transmitter modules
and also a second Taranis-X9D Radio too, trying the same several other different receivers to there different flying models.
We encountered at random times, failures of partial stick controls of the models only when using this problem internal XJT module.
Where as using external modules and using another Taranis-X9D as well, we had NO stick control failures at all.
There were no telemetry alarm being activated (sounded) during these failures.
The behavior of partial stick failure of model controls were: rudder control (signal) was changing to a far left stick (signal) and to compensate for it
the pilot would then move the rudder stick to the far right, but the quad model would still spin slowly to the left.
The Aileron stick control was not working correctly also.
This unusual behavior (problem) would happen most of the time when flying a second battery pack,
but did happen some times with the first battery pack.
The RSSI did not indicate a lost in connection.
With hours of bench testing with this problem Taranis-X9D internal XJT Transmitter radio, this problem never showed up.
Distance never indicated any cause to being a problem as the model would only be some times about 10 feet away to when
this lost of control would happen again.
This random unusual behavior showed up only when using this internal XJT transmitter module and when flying.
This Taranis-X9D Radio was working flawlessly for several months before this problem showed up and was still under warranty when
this problem started, so Wayne at Aloft Hobbies asked for this Taranis-X9D to be returned so he could have a look at it.
Wayne at Aloft Hobbies replaced the faulty Internal XJT Transmitter module (Taranis-X9D back board).
He also replaced both Gimbals which we showed was not the problem when using external modules.
This fixed the problem with this faulty Internal XJT module.
We did not find what caused this problem in this internal XJT module to fail.
Could have been a bad solder joint heating up and/or wire connection or component randomly failing, just do not know at this point.
It is fixed now and working flawlessly.
Bob B.
