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I'm suddenly having issues with the hotend fan on my RMv3. As in, if I leave it plugged in the printer doesn't advance past the firmware version screen on the LCD at boot. Unplugging the fan immediately cures the problem. I do have an e3d v6 running with the he280 pcb, and I did just do a nozzle change, but otherwise I can't figure out what changed as it's been happy for some time.

Also, if I start the machine with fan unplugged and then plug it after boot, it'll spin as normal when the hotend is activated. Any ideas?

You probably have something shorted out - it likely could have happened when you changed nozzles.

g.

That was my assumption - I just pulled the PCB and there seems to be a short between the hotend supply wires, though I can't immediately see anything externally bridged. Is there a schematic for the PCB anywhere? I don't see it on the git.