I have a very early version Wanhao i3, it lacks the slanted control box and was one of the first versions sold:
I was attempting to install the heated bed MOSFIT fix mentioned here:
However, I ran into a bit of an issue. When I got to the PSU, I noticed that the third set of COM and +V ports that are supposed to be empty, are not:
Attempting to trace the wires, they appear to be connected to the cooling fan for the extruder motor (not the fan that cools the nozzle). I don’t recall if this was due to a previous mod or not, as I recall long ago there being a recommendation to put some fan on the printer to be always-on. (I think originally it was wired in with the nozzle fan, which was not good since then it would turn on or off based on that fan rather than be always-on).
Thing is, I am not sure what to do now. I don’t recall what, if anything, this fan was connected to previously if I did just connect it directly to power long ago, and if so, if I can just also connect the MOSFET as well, or if you aren’t supposed to connect two devices to the same terminal on the PSU.
If it’s a bad idea to connect the power for the heated bed MOSFET and a cooling fan to the same PSU ports, would I be able to connect this fan with another always-on fan instead then? I am not sure how to make this work with this fan taking up what should have been a free slot for the MOSFET on the PSU, and I can’t find any sort of diagram on what each port on the PSU connects to… especially for my older model.
