I installed TH3D to my stock mainboard via this guide, but BLTouch does not work properly.
It does not check all 9 points before point it just go middle then check z then start printing. BLTouch normally needs to check all 9 points before printing or with autobedleveling but somehow mine do not work like this.
After setting up the BLTouch in firmware, you need to activate the leveling function for every print by inserting the leveling G-code 'G29' in the start G-code script of your slicer. The code should be placed directly after command G28.
Note that you can test the working of the sensor from the printer display: sensor can be deployed, stowed, reset and tested.
An alternative is to use the G29 and M500 command once in a while (for beds that don't change, don't get handled by excessive force and/or are operated at the same temperature) or store the shape of the bed through the display interface and put the command M420 S1 in your start G-code instead.
