I have recently completed my lowrider V3 build but have ran into an issue with the X axis homing. Whenever I press home the X core moves about 5mm in the Xmax direction. I took my cover off to look at the board endstop status and the LED light was on. I unplugged the endstop and the light remained on.
I also ran a M119 with the endstop plugged in and not actuated and it registered “triggered”. When I actuated the switch and ran the M119 again it still read “triggered”.
Is there a solution for this issue or is it a case of a broken board/switch?
If the endstop is showing triggered when it isn’t activated, you have an open circuit. Check your connections, especially if you are using an extension cable. Also test the switch itself to ensure you are connected to COM and NC, and that the switch is 0 Ohms between COM and NC when not asserted.
If you are using the crimp connectors, check that you crimped on the metal, not the insulation (use an Ohmmeter). Solder connections are permanent, but more effective (IMO), depending on your solder skills
EDIT - I initially misread your post, the following isn’t your issue - but you might experience it later…
There is also a known issue with the SKR Pro v1.2 endstops . But the symptoms would be different - M119 would not show triggered when the switch is activated (even though the lights are asserted). Some users claim that it affects a small number of boards, but IMO the problem is regrettably common.
You could search the forum for “SKR endstop resistor” and find dozens of threads, but in summary there are limited options:
Cut the trace on the LED (destructive, will void warranty)
Solder a resistor (1k - 1.5k Ohm) to the underside of the board at each connector VCC 3.3V to SIG terminals (will void warranty)
Fabricate a “pigtail” that jumpers the resistor between VCC 3.3V and SIG terminals on the board connector end (requires 3 pin female connectors) and connects to the endstop cables on the other end (requires 2 pin male connectors). (Does not void warranty)
I used the pigtail method with a 1.2k Ohm resistor. Again, if you search the forum for “SKR pigtail” you will find dozens of posts, but this post shows the schematic and a picture of the pigtail. I suggest making the pigtail a bit longer (4"-5" ) so that you can have the cables connect under the board, rather than on the top or side.
Did you bend or clip the Diag pins on the TMC2209 drivers?
There is a known issue on the SKR Pro that the end stops cannot work when thisnpin is connected. To my knowledge, with that pin connected only sensorless homing is possible.
I checked my connections to the board and extensions and they seemed to be OK, I do not have a multimeter so I was not able to switch.
I find this issue strange because the board has a lit LED even when the switch is not plugged in. For reference the other endstop LEDs are turned off when plugged in but not actuated.
This part is normal, and indicates a triggered end stop. The other LEDs should light up if you unplug the end stops.
Grab a jumper and short the signal pin to ground. Be careful that it is signal and not +VCC that you jumper to ground! The LED should go out, and M114 should report that the endstop is open. If that happens, your board is fine, it is the end stop wiring that is compromised somewhere.
So your board is working correctly, the issue is that the wiring between the board and the switch has an open somewhere.
Easiest way to test without a multimeter is to remove the connector from the switch and use a thin section of wire to jumper the two crimp connectors together. If that causes the LED to go out, then the problem is a faulty switch (uncommon, but it does happen). If not, then the problem is in the wiring harness.
Next do the same thing at the connection between the switch wire and the extension cable (jumper the end of the extension wire that connects to the switch wire, and check the LED). That should tell you if the problem is in the switch wire or the extension wire
Sorry for the long delay. Yes! I took apart the X core and the black wire was disconnected from the homing switch. I reconnected the switch and the issue was resolved!