Hello!
my h2d seems to be making a quiet but consistent hum.
Its not the hotend fan i believe, and I can confirm the outflow fan is not turning when this video is being recorded. Sound is incredibly faint but constant.
I’m just autistic and don’t like when my machines make a sound, so if someone could help I’d appreciate it.
Thanks for any help 
How comfortable are you about popping the back open? If not, file a ticket and wait for their instructions - otherwise
Get to the point where you can actually see the MC fan. You don’t want to replace it, nor necessarily take off the AC cover. Just visually see if anything loose is interfering with it and then start it up to get a better location of whether it’s the fan or it’s coming from inside the AC section. If nothing looks obvious, just cover it back up and wait for support for warranty reasons. It could also be the power supply, located to the bottom left of that.
Thank you for the link! its now completely quiet (at least this morning).
I’ll have to run another print to find out how it sounds, but i think your ID of the motherboard fan is correct.
The sound only started after I installed my venting system in the back, which screws to the 4 purple circles here, could that be related at all?
The bottom right purple might be close to the power supply fan. The MC and AC cover I think were next to the poop chute.
interesting, on further examination it seems the bottom right screw is the only one i didn’t put it because I ran out haha.
Ill check to see if the noise persists, since its quiet this morning im assuming it may have been related to chamber cooling?
I’m having the same issue. @Androo4u Mine gets better and worse as I move the print head via the x/y axis. I’ve put a ticket in. Any solutions? Anyone else having this issue?
same problem here. get you an answer from support?
oh my! I didn’t realize my post would get necro’d.
My problem went away? My assumption is that it was a fan keeping components cool when the chamber was heating.
Sorry about your problems, I hope it gets better/fixed by support.
I just got my H2D, and when the printer is idle, I hear a faint fan sound from back of the printer. I don’t want to turn off the printer completely. Is this fan supposed to be always running?
is it on after a print? like i said it may be some sort of MOBO cooling fan
No, it’s always. I even left it alone at night and came back to check in the morning and it was still going. Turned it off and turned it back on a few hours later and it was still happening.
It sounds like a computer fan.
do you have a vent/poop chute that is blocking any exhaust on the back?
Nothing blocking it. I can’t attach images since I’m new here but there is 11cm between the wall and the printer.
no idea then 
sorry friend
The sound could be from the stepper motors.
It is not unusual and my printer has a faint sound as well, It is only when the stepper motors are engaged.
I have a very loud sound (not grinding but almost) which seems to be coming from the same area. If I gently tap the outside of the printer case (under the back exhaust flaps) it stops for half a second then keeps going so I know it’s from that area.
I’ve recorded the sound but not sure if it fully grasps how loud it is.
I’ll get a ticket opened, but should I be looking to the mainboard fan too? I’ve opened the filter area as seen in the video and can’t see anything that would be the issue.
The switching power supply fan might be the noise it just below the ex vent flaps.
I now have the noise too. It wasn’t there at the beginning. I have the feeling that it only started after the second beta update. I did not install/receive the first beta update.
As already written here, as soon as you move the print head a little, the smoke is no longer there. It is definitely due to the stepper motor.
