Hello, I recently got my KSGER T12 setup and have been doing some soldering with only a single uncalibrated JL02 tip. Just got a bootleg FG-100 to calibrate the tips I have.
- I first calibrated my JL02 tip, and calibration went successfully (has the asterisk shown when the tip is selected).
- Next I attempted to calibrate my C1 tip, but the result every time after the third phase of the calibration is the “Cal Failed!” error. I have zero clue why this is when my other tip calibrates just fine.
Anyone have experience with this issue care to share some knowledge?
I remember having this issue when i installed the open source CFW avaliable for the KSGER stations. There was options in the settings to adjust something which i think (don’t quote me) affected accuracy, sorry can’t remember for the life of me what these setting were but maybe there is something similar in the FW your unit is using so it may be worth checking the CFW guide / or EEVblog dev posts to see if there is something similar in the stock FW your end which you can tweak to correct. (assuming your unit is using stock FW)
Alternatively, you may have to be less strict with you cal routine for this tip to avoid the error, i imagine the issue is it’s semi far outside of the max / min allowable in each stage / range, maybe as a result of bad quality TC inside the tip or as a result of tip manufacturer differences or something. Try being +/- 10C off in increments and see if that clears the error.
Option the third, if that doesn’t work or there is no options in the settings to tweak / correct, maybe look into installing the open CFW, it was pretty alright when i last used it but kindof unfinished so i went back to stock FW on mine but I imagine it’s probably polished up nicely since then as it was a long while ago I tested and should allow you to correct for this issue 
Also worth noting the FG-100 tri point probe thingy, after you’ve used it a couiple of times the readings do tend to wander off what is actually accurate compared to using a fresh probe. I found adding some flux and very briefly running over the central point with some solder wick restored it’s accuracy… dunno, maybe solder gets under, brinding the tri wires throwing off accuracy slightly.