Hot End Strikes Buildplate

Hello,

I have a Wanhao Duplicator 6+, and it has been a nice printer, but unfortunately it now raises the buildplate into the hot end for every single print. I have contacted Wanhao customer support, but they have stopped responding to my requests for any information that can help me diagnose the issue.

Here are the symptoms:

If I go into advanced setting and manually drive the buildplate up or down, down works as normal - one button click sends the buildplate down a set amount, and repeated clicks are required to lower the plate more; however, if the printer is instructed to raise the buildplate, after a single button click, the buildplate will be raised until it is jamming against the hotend and I have to manually turn off the printer.

If I go through the auto-leveling process (as instructed by customer support), a similar issue occurs when the buildplate will be raised too far and strike the hot end.

If I start a print, the same occurs as well.



I am confident that the issue is not the proximity sensor as 1) the red light turns on when the buildplate or my metal spatula are close to the sensor and 2) I have already replaced the sensor per customer support feedback, and the issue is not resolved. I assume there must be something between the proximity sensor and the z-axis drive motor that is failing, but I am not sure what to test.



Other damage locations that might be causing the issue:

Since the first time that the hot end struck the buildplate, it has damaged the surface of the buildplate. There is now a small round indentation that has damaged the blue film on the buildplate, so if there needs to be a particular electric signal running through this (as discussed in the Zortrax troubleshooting guide linked at the bottom), then maybe this needs to be fixed?

Also, the design of this machine has the hot end power cable running through a plexiglass cutout in the back wall of the machine. This cable rubs against the plexiglass and the right side (when viewed from above) has worn off a little bit. I don't think the damage is serious as no cable is showing, but if the wire on the right side sends signals to/from the proximity sensor or something else that ordinarily would tell the achine to stop driving the z-axis motor, maybe this needs to be fixed?

This machine is a clone of a Zortrax, and I did find this troubleshooting guide; however, as the systems aren't exactly the same, I don't believe all of this is accurate to my machine.
https://support.zortrax.com/troubles...forated-plate/


Any direction or assistance would be appreciated. This printer has been out of operation for many months now, and I don't know why customer support hasn't gotten back to me in over a month.

Thank you,

*Update*

I was able to get in touch with their customer service again. They had me run through the same checks on the proximity sensor and make sure the printer had the latest firmware, but the ultimate solution for me anyway was to replace the 10-pin extruder cable.

After taking off the old cable, the visual damage I saw wasn't the culprit as the damage was superficial; however, the cable did have a loose/intermittent connection to the extruder.

If I pushed the cable down or to the side of the extruder to cause the pins to temporarily make a connection, I could get the printer to recognize that the print bed was within range.

I swapped out the extruder cable for a new one, and the printer is now working as it should.