Stay with us. There may be some hope.
With help from
@markux and
@Steve Carr, this issue was revisited. Ultimately, there is still no readily available recovery from a “bad update” bricked ST-10. This project did reveal some items that have not been posted, and these may prove useful to others.
Discussion:
The issue in this case, (and many others) is that the ST-10 was updated with ST-10+ firmware that is not compatible with the ST-10 video (Build st10+v01b31c). The screen is essentially blank (heavy dark gray lines across the screen) and the touch screen features are not available.
In this project, the affected ST-10 mainboard was temporarily moved to an ST-10+ controller to give it access to a video compatible with its new firmware. That part of the project worked well. Normal screen visibility and functions were restored. (It is highly questionable if this will work if the problem was caused by an attempt to load COMPATIBLE firmware that simply “went wrong”. Those would be case by case situations depending on WHAT went wrong.)
With normal screen functions restored, it seemed like the solution would simply be to undo the update. It only “seemed” to be so.
Attempts were made to reload several versions of the ST-10 firmware updates. No problem with the Tx portion of the update. They can apparently be loaded and replaced at will. The issue came with the “SYSTEM” portion of the update.
The “system” portion of the firmware cannot replace the existing update with an earlier version. The device will attempt to update, stall, reset itself, attempt again, and repeat for about 5 cycles, then fail out to the android error screen.
The “Reset” and “Factory Data Reset” are not true factory resets. They only erase settings and data created by the user. It returns the system to the current version firmware update.
It appears the only way to revert the mainboard to a compatible firmware version is to reset the software similar to doing a “reimage” of a PC. You may be aware that many android cell phone manufacturers make the firmware and programing available to the consumers. However, Yuneec apparently has not made the equivalent resources available to the general public (at least nowhere I have found).
Summary:
You still have to replace it, or send it to Yuneec for repair.
Additional Observations:
1. The problem ST-10 mainboard can sometimes be moved to an ST-10+ controller to get access to its video functions.
2. The ST-10+ controller SEEMS to work normally with the ST-10 mainboard installed. Only two brief flights were made, both at low altitude, minimum distance, and no challenging maneuvers, but no problems were immediately apparent. This may be worth considering as an option under some circumstances.
3. The ST-10+ controllers did NOT work perfectly when the ST-10 Wi-Fi/flight control board was installed. I only had one ST-10 Wi-Fi/flight control board, and perhaps that board has an issue, but when installed in two different ST-10+ controllers, there were “hardware monitor” issues with the J1 (up/down) and the J3 (front/back) controllers having a positive bias. One controller had a relatively severe issue that made flight almost impossible to control. The other had a minor issue that only created a noticeable “drifting”. Again, this COULD just be a problem with this particular ST-10 Wi-Fi/flight control board. The problem with the Wi-Fi/FC board related drifting occurred both when the ST-10 mainboard was installed, and when the normal ST-10+ mainboards were installed.
Update 2019-03-03: This issue was caused by installing the flight control board in a different ST-10 case without recalibrating it to the input devices of the new controller. Refer to thread https://yuneecpilots.com/threads/calibrating-st10-and-st10-flight-control-board.15862/ for a discussion of the need and method of doing the required calibration.
4. You cannot put an ST-10+ screen in the ST-10 controller. It is too large for the ST-10 frame and the screen end of the ribbon connector is a contact fit that would be very difficult to align without the frame support.
5. Some attempts were made renaming files. It did not change the results.
6. The Android error screen includes some options that can be highlighted by the (+) and (-) keys. One of the options is to “apply the firmware from the SD card”. This option may (or may not) produce a different result. However, I found no way to “trigger” the option (no equivalent to an “enter” key). If someone knows how this is done, it would be useful to know.
And by the way, I don’t know what the microphone is for either. Maybe someone else does?
