error code m999

[technoob1980]

hi there

just installed the bigtreetech skr mini 3.0 . having trouble getting the bl touch to work with it. tired all the firmware updates and nothing. i will home it and it will go to the center of the build plate. the probe will do its thing but the z axis will not go down to the build plate the i get the error code m999 restart. i dont know what that means. 

[fatboy1271]

Check your BLTouch black and white connectors. Make sure the polarity is correct per your board. I had to make new ends to correct M999 on mine. Works great now!