Yuneec st16s dead stick

[Stephen1988]

Have a yuneec st16s for h plus. Right joystick seems to be dead, j3 and j4 are always in the down position. Ended up with a small crash because of this . Opened it up, wire is connected so tried disconnect and reconnected and still dead, tried a joystick out of a h480 in it to see would that work as it’s the same connector but still dead, the joystick for the 480 is slightly different if u were to screw it in but was just to test. My question is if it was the joystick at fault should it not stay in the middle and not bottom setting. I’ll add a picture to try explain better

 

[Stephen1988]

Have a yuneec st16s for h plus. Right joystick seems to be dead, j3 and j4 are always in the down position. Ended up with a small crash because of this . Opened it up, wire is connected so tried disconnect and reconnected and still dead, tried a joystick out of a h480 in it to see would that work as it’s the same connector but still dead, the joystick for the 480 is slightly different if u were to screw it in but was just to test. My question is if it was the joystick at fault should it not stay in the middle and not bottom setting. I’ll add a picture to try explain better

so a bit of an update, I tried disconnecting the stick on the other side to see would it give me the same symptoms with the both bars going to the bottom position and not returning to middle which u would think would be the default position. Bit of a mixed result, one remained in the middle, I think it was throttle and the other did in fact go to the bottom. I then unscrewed the good stick and connected it to the side where the dead stick was and still nothing, both in bottom position. It’s almost like no power is going to this stick. Has anyone ever had this issue

 

[WTFDproject]

I tried unplugging the sticks on two spare ST16S for HPlus. The results were exactly the same between them:
Two sticks (J1 and J3) remained in the center.
J2 went to -25%.
J4 went to +25%.

Your troubleshooting seems to suggest the gimbals are both good since both left and right behaved the same in the right position. It would have been good to try the right gimbal in the left position. But even then, it would be inconclusive.
Your issue could be still be other hardware, such as a bad board. Or it could be firmware. Or it could be issues created by the previous owner doing something.
The easiest thing to try would be a factory reset and reload the Flightmode APK.
If that has no effect, do a firmware downgrade followed by a firmware upgrade.
If there is still no change, the issue is not likely firmware or the previous owner.

 

[WTFDproject]

Did some more experimenting. I unplugged both gimbals on one of the spare controllers and tried to do a gimbal calibration with the sticks unplugged. The results are pretty similar to what you see. J1 and J2 are stuck at the top. But J3 and J4 are both at the bottom. Maybe a previous owner did something similar.
Now I will go take some of my own medicine and see if it helps anything. (After I simply try another stick calibration with things plugged back in.)

 

[WTFDproject]

The stick calibration was all it took.
Directly after stick calibration the RC Monitor showed all four sticks in the center, but none would move at all. Turned off the controller, counted to five, turned the controller back on, and now all four sticks are working perfectly.

Possible conclusion:
It is possible the previous owner had a bad gimbal and tried to use calibration to fix a hardware problem. This theory includes the right hand gimbal may or may not still be the original bad gimbal. If you try a calibration and either(or both) gimbal is still bad, your are going to get the same or similar bad results. Do something to ensure both gimbals are in good working order prior to running the calibration.
Also be sure both gimbals are plugged into the correct connectors. The trim tabs use the lower connectors, the gimbals the next connectors up. Another theory could be the previous owner did the calibration with the gimbals swapped with the trim tabs.

The third theory, unfortunately, is that my experiment resulting in similar results was nothing more than a fluke and has nothing at all to do with your problem.