Z axis wont lower

Odd…my z axis is stuck about 2/3 the way up…it will raise, but will not go down past where its stuck.

Printed like a champ for weeks, now my z axis is stuck. What could be the issue?

I can disable steppers and manually lower the x axis bar, i can move the bar up using it he printer controls, but it will not lower that way.

Ive got a funny feeling something is off with my BLTouch but idk.

My first thought would be the limit switch. It being stuck in the closed position would let your Z axis go up but never down. Check this first. If it seems to be open then unplug the switch, if it works then, then the switch is bad.

Limit switch is unplugged. Let me take a video of whats going on…one sec…

Remember, if it starts to move with the switch disabled, when it reaches the bottom you could damage the nozzle, print bed or the drive gear, be quick to turn off before it reaches the bottom.

Cant upload video.

No it doesnt move.

Basically what happens when i try to home, X and Y home perfectly, the nozzle then goes to the middle of the bed, but just stays there and the bltouch needle does not deploy. It just stays there and the screen says “STOPPED”

The switch that is being used may be a normally closed switched, short the two wires and see if it works then.

I unfortunately dont know what that means “short the two wires”

If that does not work, the only thing else I can think of is the circuit on the motherboard could be bad. I am not familiar with the circuitry to tell you how to check that. Hope someone else can advise you. Before some one else can help you need to post what printer and in some cases the type of motherboard it has. In some printers, they will have several motherboards depending on how new it is.

What I mean on “short the two wires” is to bridge the two wires with a short piece of wire. The switch itself should only have two connections.

More reading leads me to believe the connection to the board came loose. Later today ill reattach it with hot glue.

Oh, and Ender 3 V2, V4.2.2 board


The GD bltouch wire became disconnected from the motherboard because its a VERY loose fit. A dab of hot glue and we’re back in business. ?

I have heard of this when the BLT has multiple Dupont connectors on the control board side, instead of a single JST XH connector. 1 way to tell is that Dupont connectors are almost always black and JSTs are mostly white. The Dupont connectors simply do not fit tight enough into JST connectors, which is what is almost always on control boards. For example, the connector on the BL Touch itself is JST.