Marpac / Dohm Classic Rattle Fix

I have been using Marpac / Dohm Classic noise machine for some time and have found it very useful and durable. The only thing that might occur overtime is rattling noise I thought might be due to fan being misbalanced, shaft or bearings worn out or any mechanical issue. At some point I even used it upside down because that way it wasn’t ratting. I did regular cleaning of insides and lubing (with wrong lube in wrong places) but the solution was hidden in plain sight. Short answer: felt on the bearings should be lubed with thin oil. The easiest way to do it is a can of WD40 with a straw. The best: is disassemble everything, clean and use specialised oil for this type of motor. People who will use this method are not in need of guides like this. Let me guide you through the steps of easiest way.

The tools you need are quite simple. A medium philips screwdriver, simple pry tool a can of WD40 (original stuff is the best but you can use whatever is available in substitutes of spray can thin oils)

Disconnect device from power and put it upside down. There are two screws, use screwdriver to unscrew them.

There are four hooks still holding everything in place, try use pry tool or any other pointy object to slightly unhook them while pulling body apart. Those are quite easy, no worries on braking something, you wont.

When you open it, insides will look like this. Yours might be much more dusty. Use microfibre rug, air blower and soft brush to clean it up. Note that fan made of very soft metal and it will bend very easily. It not a big deal but its better not be allowed, so be gentle.

Our points of interest here are two points INSIDE the shaft of the motor. Inside of those there are pressed in felt material to keep oil and oil canals for lubrication pointing against each other.

Shake the can of WD40 and point straw directly to bottom bearing. Spay it by tapping the button on the can. You don’t need to hold it more than a tap. Let the foam to settle for a few seconds and soak the felt.

For the upper bearing you need to rotate device upside down. Remember that canals are pointing down on top bearing. Tap another lube squirt from can and keep it all upside down to settle for a few seconds.

Now place the the upper part of the body back and screw it down the same as you did in first steps. Put the plug into a socket and check that device operates normally and without rattle.

Voila.

From my experience you should clean it up and lube it yearly and it will keep it working forever. My noise machine works 24/7 without the problem for a few years now.