In the past few days I had a problem with my new BLTouch. It stopped leveling the bed partway through. I would start a print, the axes would home (including the Z), then it would start the 9 point bed level. At point 2 or 3 it would start firing the probe up & down repeatedly and then the LCD would display STOPPED.
I looked at a number of things, but the fact that it just started out of the blue made me suspicious it was a hardware issue. After checking other things, like reseating the Z axis limit switch connection on the control board, I homed in on the connector to the BLTouch sensor. Here’s a photo:
The thing to notice is the white & blue wire connectors. I had noticed that both of these connectors were exposed when I 1st got the BLTouch, but, because both end connectors looked much the same, I assumed this is the way it’s supposed to look. And, the BLTouch worked, which reinforced the idea that all was well. It isn’t.
I used to have 20/5 vision in my left eye & 20/10 in my right so, decades ago, I would certainly have noticed that there are 5 wires but only 4 little plastic ‘retainers’. Since I’m now developing cataracts, and need reading glasses most of the time, I didn’t notice it until looking at the photo. I did not do this: the cable was like this when I got the package.
In any case, closeup inspection revealed that the white wire’s connector was not making good contact with the sensor – it had worked loose after a number of prints. I very carefully reseated the connector, paying special attention to getting the white wire fully connected.
I looked on Amazon to find a kit of JST connectors the same size as the existing 1. I believe it’s a 1.25mm or 1.5mm, but I’m not certain, and I haven’t been able find a spec sheet that shows it. Also, I could only find 1.5mm connectors on Amazon. I guess I could order the 1.5mm kit and return it if it doesn’t fit, but I don’t like abusing Amazon’s return priviledges. I guess another option would be to use hot glue to anchor the wires in place.
I will look in my trove of spare wires & parts to see if I already have the right connector.
Returning the BLTouch isn’t really an option because I ordered it off AliExpress… it would take forever to get a new cable.