Welcome to the SeeMeCNC Community

I'm new to the forum, and I've just recently built a Rostock max v2 kit. I'm having issues with the layer fan though. I have it connected properly the rambo board, but it seems to work in exactly the same way as the Peek fan, which is puzzling. I have no control over the layer fan, as it kicks on at 50 degrees hotend temp, just like the peek fan does. Nothing I seem to do in software seems to have any effect on this.

When the system is off, the positive terminal for both fans are connected, when continuity tested with a multimeter. When all wires are disconnected, these two terminals are not connected. Also when disconnected, the positive leads for the fans are not connected.

Has anyone run into this problem? I've emailed support, but they've yet to give me a solid solution, and keep telling me to connect the layer fan to Fan0, and Peek fan to Heat1, which I have checked and rechecked. I appreciate any help anyone can give me. Thanks!

Shut power off on Rosock Max.
Unplug USB cable if connected to PC.
Remove layer fans wires from Fan0 terminals on RAMBo.
Connect multimeter leads to Fan0 terminals. Set meter to VDC.
Turn Rostock Max power switch on.
Should have no voltage on Fan0 terminals (may show ghost voltage on non true RMS meters).
On Rostock Max LCD screen, navigate to Adjust Fan Speed > Turn Fan to 100%.
Should have 12V on Fan0 terminals.

If that all checks out properly, I'd ring out the continuity (and isolation) of the 4 #26 fan power wires going up the tower. There may be a crossed or shorted wire among them.

I went through this process and when untethered to the pc, the fan 0 terminals have no voltage with the fan off or on. Also, the continuity of the fan wiring through the tower checks out fine. Any thoughts?

I would try reloading the Repetier 0.91 firmware via the Arduino IDE process and check again. If still bad, contact SeeMeCNC and tell them you seem to have a defective RAMBo.

all positive terminals on the rambo are linked... they are all switched via ground.. you said you have all the positive terminals connected, but didnt mention the ground ones, you dont happen to have them tied together do you? the positives dont matter since they all have power whenever the machine is on, but the ground wires are important because thats how they are switched on.

Guanu

Nothing is physically connected to each other, there's just continuity between them, which makes sense if they're controlled via ground. Assuming nothing is wrong electrically, is there something firmware related that could cause this issue? I have control over the layer fan with the hotend off, but whenever the temp reaches 50, I lose control and it spins up with the peek fan. From there I cannot turn it off or change speed in repetier. Has anyone seen something like this before?

is this on an orion or rostock? it sounds like the grounds are definately touching somewhere.. to find out you can run a test by disconnecting the layer fans ground from the rambo but leave the positive on, since they are all common.. if it turns on when the peek fan turns on, the grounds are touching somewhere...

Guanu

Its a restock. I checked what you suggested and the layer fan doesn't spin with the ground disconnected. I ran the extruder up to 60 so the peek fan turned on, and I still had layer fan control. I'm guessing its working properly now, but I could have sworn I didn't have continuity between and fan leads. I'll go back through and insulate the connectors more later and try a print to see if its working correctly. Maybe something vibrated into a different position while it was running. Thanks for all the suggestions!