My first TH flew away after about 100 flights. Bought used Typhoon H Pro and it worked like new for 50+ flights. I then noticed that I could not perform any calibrations, esp compass. I had calibrated all many times before. On last flight, only went up about 15 feet, but drone slowly drifted to right and I could not get response from sticks. Since it was headed toward a tall bush, I killed the motors as it touched the bush. It fell to the ground, but branches slowed the fall so the only visible damage was a broken prop. After this crash, I again attemted to calibrate, but would not work. I had a spare ESC board and what I believe is called the flight control board which came attached. I replaced both in the TH. When I was ready to test, I was not able to bind the TH to the ST16 because the TH would not display under the "Aircraft Model" in the System Settings screen. I watched many vidieos and followed instructions to copy aircraft, put TH into bind mode, had blinking yellow light, and tried to update software. The cgo3+ camera would bind and even the tilt, pan, and rotate functions worked as they should. I also pressed Reset, Refresh, and Bind MANY times, but still cannot get TH to bind. There is no telemetry on main screens and motors will not start ( props off of course). I have not been able to find any thread or discussion that deals with my situation. Does the flight control board have firmware embedded from factory or do I need to down load. How can I do download if I can't get ST16 to "find" the TH since updates are started ftom ST16? I noticed that many updates and downloads were either gone or non-functioning so I tried from Yuneec Skins website, but not clear which ones I need to download. It seems that I am at least partially bound to TH since the rotate/tilt of camera works. I have also went into the android menus and cleared flight cache per several videos. Have also made sure wifi is enabled and have entered password into ST16 when attempting to bind. I apologize for such a long post, but I just wanted to describe all of the things I have tried. I don't know if this is a hardware or software problem. I do have Realsense installed if that matters, but I am not sure that it was working, even when I first received. Help please...don't know what to do to fix. Thanks in advance for your advice !!