We just bought a new SV04 and have set it up according to the manual. Right out of the box however, it refuses to home the Z axis. Most of the time we can use the Move menu to use the gantry up, but not down.
To me, this sounds like an issue with the CR touch sensor. During startup, the pin comes out twice, but then it does not extend the pin at all during homing or leveling. The LED on the CR touch is red constantly.
Does anyone know how to diagnose this, or should we send the printer back?
Hi Niels,
how to run touch sensor tests is decribed here - it will work both for BL-touch and CR-touch sensors: https://www.3dprintbeast.com/bltouch-self-test/
You’ll need a tool like Pronterface (Freeware) to initiate the mentioned G-Code test commands via USB connection from your computer.
If the touch sensor is still not working you may want to try the trouble shooting instructions suggested in the following link [Caveat: I won’t recommend changing firmware before being sure that there is no mechanical or electrical/wiring problem present]: How to Fix Auto Leveling Sensors Not Working - BLTouch & More - 3D Printerly
Additional documentation can be found here: https://3d.nice-cdn.com/upload/file/BLTouch_Manual.pdf
Thank you for your quick reply. We ran the self-test but it does not respond at all. The drop pin (M280 P0 S10) command also did not do anything. With the printer connected to Pronterface we tried homing which results in the following error:
Error:!! STOP called because of BLTouch error - restart with M999
Error:!! STOP called because of BLTouch error - restart with M999
Error:Printer stopped due to errors. Fix the error and use M999 to restart. (Temperature is reset. Set it after restarting)
Error:Printer stopped due to errors. Fix the error and use M999 to restart. (Temperature is reset. Set it after restarting)
Error:!! STOP called because of BLTouch error - restart with M999
Error:!! STOP called because of BLTouch error - restart with M999
We suspect the wiring might be at fault here, but it is a little hard to check. I searched for the wiring schemes of the SV04 yesterday but I could not find any. Do you by any chance know what the wiring scheme is supposed to look like between the main board, the flat cable breakout board, and the sensor? We are equipped to measure low-voltage signals.
Niels, you’re welcome.
Did you reset the BL-touch alarm-mode by sending a M280 P0 S60 or M280 P0 S160 gcode command before the drop pin command? If not the behaviour you observed seems to be correct (in case a touch sensor error had been noticed by the firmware before).
Did you try to pull out the probe pin manually a little bit when it should extend? Maybe there is just a little bit of obstruction in the wrong place…
We have not tried resetting - I’ll try that as soon as possible. We have tried to ‘help’ the pin a little, that does not work.
I have measured the signals on the sensor wire without the sensor connected:
W - GND
K - Vcc
Y - 3v3 PWM signal
R - GND, continuous to W
B - Also measures a PWM signal, around 1V.
The fact that I observe a signal on the blue wire without the sensor attached worries me a little, if that is supposed to be the wire carrying the signal from the sensor there is possibly either a short to the yellow wire, or some crosstalk.
Edit: I tried sending S60 as well as sending S160 before S10 and S120, but neither gave a different response.
One more thought about the wiring: Are the yellow and blue wires swapped between CR-touch sensor and the SV04 connector wires? According to the pinout diagrams this should be correct.