There was originally some discussion about the area of use being part of the issue and that portion will be omitted.
AH-64D:
Just posted to my original query thread about replacing batteries that I ran ST16 calibration tests and then hardware monitor. The tests show J1 is bad. Hardware monitor shows it is slow to settle back to its null point. Should I blast that stick with CRC QD Electronic Cleaner and repeat calibration test several hours later?
DoomMeister:
I would suggest cleaning the potentiometers using the method outlined in the document attached to this post. It also covers things to observe about the mounting of the potentiometers. We have also found the small JST connectors at the stick gimbals to be part of the issue. My original ST16 was terrible about oxidizing and since soldering those wires directly to the board at the stick gimbals I am not having to spray the potentiometers anymore. If you are good at soldering it is not a difficult task, if not leave it to someone that is.
The other thing I forgot to mention is that cleaning and getting good response in Hardware Monitor should be done before ever doing the calibration.
Another thing came to mind. The slow return to center may also be related to the potentiometer for J1 being loose in its mounting.
AH-64D:
Very Good points DoomMeister. Saw a good YouTube video on opening the ST-16 case. Will look at the document you posted, open the case to clean the things from the inside and decide whether I want to solder the connections. I do have the tools and experience to solder the leads but the last soldering I did showed my age. I will consider that factor before heating up an iron.
Just checked and found I still have a decades old spray can of Cramolin B-5 PreservIT. Used to use it to clean electrical contacts of oxidation. Using it may have a better result than my efforts to solder closely spaced small wires. Will put some on a swab and check to see if it is OK for plastic of the gimbal assembly. However, first things first. Will first clean things with CRC QD spray and determine if that is enough to resolve my J1 problem.
DoomMeister:
Those wires are small and closely spaced. Requires a small tip, about 300 C for temp, tin the wires, get on and off quickly to avoid delaminating the pads. If I remember correctly I used pads near the ones that the connector is mounted in.
When using the QD to clean the potentiometer spray it then vigorously stir it. You can also swap the stick gimbals to see if the problem follows the gimbal or stays with J1.
AH-64D:
The QD spray can lacked its small tube for directing spray at a restricted area. The Cramolin can had its nozzle tube and a test wipe showed that it did not harm the plastic TX parts. I used Cramolin on J1. I removed and replaced its cable 2x at J1 but was unable to free the other end of the cable where it attaches to the mixer (?) board. I wiggled that connector as I sprayed it. Hardware test showed some J1 improvement, but it still flunks the calibration test. J1 seems to lack the necessary range to pass the test at this point. It does now settle quickly at null position, but its width at null is wider than J2 in the hardware monitor. I have opened the ST16 back up for another go. The Typhoon most likely did fly with J1 bad based on its noted "Stuck in Rabbit" flight behavior. I think I will install the replacement FCB in the Typhoon when it arrives and learn if a bad FCB is the problem.
Thank you for the soldering tips. My related best solder job was replacing an internal 1/4 wave wire antenna of a 350QX with an external half wave dipole antenna by removing the wire antenna from its board and soldering a UFL socket in its place. My worst solder job was attaching the ESC leads of a quad to its power distribution board in a "Build Your Own Drone" class. Since the class was much more recent than the 350QX solder work, I concluded that age does not improve soldering skills. I will only solder as a last resort.
Swapping the stick gimbals would be edifying, but it would also require me to disconnect and reattach the larger cable connectors at the mixer board. That may break something.
Got everything to pass after another go at cleaning J1. It passed hardware and calibration tests. The hardware monitor shows its width of position at null the same as the other controls. Now have to do compass and accelerometer calibrations if I find that I can get GPS lock when I turn on my Typhoon. To try that out, will have to charge a flight battery.
Oh, almost forgot to mention - This time, was able to disconnect the big plug that couples J1 and J2 to the mixing (?) board. I just had to figure out how to unlock the connector. Cleaned those connections also, using both QD and Cramolin.
Curiosity got the best of me. I turned things on with the Typhoon sitting in the bow window seat. It quickly achieved lock. I started the motors and got them to throttle up. Got 5 motor warning very quickly so shut down and prepared to charge batteries to do necessary calibrations...
DoomMeister:
That is good news! All three JST connectors for each gimbal have a tendency to get the invisible oxidation on them. They still appear shiny, but are not as shiny as they should be. Part of your issue with J1 could very well have been with the larger connector on the mixer board.
Way to stick with the troubleshooting and working until you get rid of the problem.
AH-64D:
Just added to other thread that I had calibrated compass and accelerometer while in GPS lock today; verified lock by getting camera to watch me only to then lose lock as it sat in my yard. I believe that I have been flying for months without noticing that I had GPS lock problems and only began to question things when my Typhoon was grounded by J1 issues.