The new SKR boards are pretty sweet, but they’re currently in v1.0, and that means bugs. Cheap Chinese parts, poor QA and a price tag of a Dominos pizza, too good to be true? Right, so the 5V line that powers the BLTouch is shite, it’s really choppy. Here’s a pic from the 5V line on a scope, as you can see, it’s naff. This is causing the BLTouch to smash your nozzle into the bed when it auto-levels.

So how do we fix this? There’s two things to do for a sure fire fix that I’ve found, firstly in your marlin configuration_adv.h search for and enable: //#BLTOUCH_FORCE_SW_MODE by removing the //

Secondly, adding a 100nF ceramic capacitor between the VCC and GND pins on the BLTouch:

Pretty straightforward way to fix the issue. Obviously we all wish we didn’t have to “fix” a brand new board, but it is what it is.