fan connect to J28

Hello, every one I am new here.

I recently bought a smoothieboard x4 to replace a azteeg mini x5 that I have blown with a short from the hot end cleaning it, well I have learned some stuff and now I got pretty much every input and heater with fuses.

Now I also have an E3Dv6 hot end and I got the idea that since I use the jumper J28 already to power the mosfet from VBB how much of a bad idea would it be to plug my hot end cooling fan in the J28 jumper leaving me with 1 slot for the hot end and 1 slot of a layer cooling fan since the hotend cooling fan requires no control except ON.

Would I need to put a diode in there ? my layer cooling fan is a 24v 0.08A.

Also my layer cooling fan is a 5V and my psu is a 24V having looked in the docs and the forum I saw some people talking about plugin it in the LCD gpio pins I do not mind however, will I need a diode there as well? I’m becoming paranoid about blowing this board as well it’s going to be my 3rd one this year, so this time I am going to ask for help before I need to spend an other 300$

Thanks you all for your time.

-Alex

Imported from wikidot