Thanks @dc42! I'll try to update with the results after I'm done wiring everything.

Howdy, I'm in the process of converting a Monoprice Maker Ultimate (Wanhao Duplicator 6) from it's busted Wanhao board into a new Duet Ethernet.

I want to use the ribbon cable/wiring that already goes up from underneath the printer to the hotend. I took the wiring out and probed it with a multimeter.

Here are some pictures I took of the wiring I'm referring to: https://photos.app.goo.gl/so91uxHR1HgP6nRA8 and I made a quick diagram of the wiring as I understand it on the Wanhao interface board. I've also added comments to each picture.

I found these resources already with details about the old board. https://3dprint.wiki/reprap/wanhao/duplicator6/major_components/motherboard and https://docs.google.com/spreadsheets/d/1XX6I6iNZCkVIueA0zD95mo8jjTG3_VZ3gDfGH6G9hfs/edit#gid=237340617 which was a great starting point for me.

After probing the pins, I labeled them with masking tape and found something interesting and here's where my question actually begins.

How does the Duet expect things to be wired? Specifically the T0 heater, the PWM fan and the always-on fan.

The pins/cables I have available are

• 24V(+) (4 of these)
• T0 heater (-) (4 of these)
• PWM (-)
• Fan (-) (always on)

My problem is that all 4 of the 24V lines are connected (shorted?) to each other so if I plug in T0 heater and the Fan(+) then it might cause the heater to be always on or something. I believe that Wanhao's board uses different logic to power on the fans and the T0 heater than Duet wants.

Should I be able to connect a 24V and a PWM (-), a 24V and the Fan (-) and the 24V and the heater and plug them all into the Duet with no issues?

Let me know if I can make anything clearer or answer any questions about this. Thanks in advance!