jmdl101

Just wanted to update, my xt12g working better than I was expecting. Stayed on Jupiter for a couple of hours with only needing to bump it once or twice. I did learn another important lesson with the encoders, especially the motor encoder. If it can't "see", it won't work. I had accidentally pushed the encoder wheel in too far and it was touching the sensor, so I would push the arrow button but it wouldn't move, or it would jerk around instead of turning smoothly. Goto and high speed rates worked because it would move enough, but tracking and slow rates would not work. After taking it apart and setting the encoder wheel correctly, everything is working awesome.

Stopping in to post another successful repair, thanks to malc-c, and some of the things we learned. This is the story of my old xt12g with synta mc004 Rev f motor boards. I had the dreaded "no response Azm axis" on the hand controller, leading to a blown pic on my xt12g Azm board (there was actually a hole burned in it). I'm in the US, so sending my board to malc-c would have been pretty costly, so he helped me through the process entirely. I ordered three 16f886's, a 28 pin clip in adapter, a pickit2, and some dupont connectors from aliexpress (tool about 3 weeks). I tested every component I could on the boards to make sure nothing else was broken, and couldn't find any other problems than the 16f886. I programmed all 3 pic's with the mc004 209 hex files from malc-c and went to work. I ended up lifting 4 pads from the pcb, lesson learned, don't pry up on the legs. I went back and clipped the legs with my 3d printer clippers, worked perfectly and cut clean. I removed the legs with my soldering iron and cleaned the pads up with solder wick. I jumpered the legs that were missing pads to the right connections, and luckily I didn't damage anything beyond that. Here's where we really started learning new things. The hand controller still showed the no response message, so back to troubleshooting. I used the uart tool on the pickit2 to try and communicate directly with the 16f886, but got no response. I took a day off at this point because I had been working for hours trying to figure out what I had mis wired to cause the problem. Then today, with the other board, I compared each pin voltage to ground and found that pins 9 and 10 were not working correctly on the new pic. Pins 9 and 10 are the crystal oscillator pins to x1. This definitely explained why I couldn't communicate with the board. I read through the 16f886 documentation to get some baseline knowledge of what I was looking for. I decided to hook the good board to the pickit2 just for fun, and got the 16f886 to communicate just fine. I couldn't read the chip code though because it is protected. At this point I noticed the configuration bits were different than what I had programmed to the new pic. After some reading, the bits set the functions of the chip internally and what pins do what. I decided to test it out, and reprogrammed the new pic with the Alt board configuration bits set. After flashing it, I got the chip protected warning, but I also got the right voltage on pins 9 and 10, me sing the oscillator x1 was on. Checked communication with the uart tool, and it worked, responded back with the firmware version I had flashed. I hooked everything up with the hand controller, and went to the main screen with no warnings! At this point I flashed the 209 firmware through the hand controller to make sure both boards were the same version. The I tested both boards with the motors just to make sure before putting the scope base back together, both completely working again. Tldr: repair was very easy, the 16f886 had to be configured correctly when flashed to work properly. The 16f886 firmware hex file configuration bits were set to 3FFA 0700 initially, but need to be 2FA2 0500 to work on the mc004 Rev f for the xt12g at least. Thanks to @malc-c@malc-c and this thread that Google found when I ran the search a month ago. My busted xt12g is alive again!