Power Supply Fan Upgrade [Tutorial]

If you’re like me, you love your Taz 4/5. If you’re like me, you hate how loud the fans are.

I upgraded the power supply fan to an ultra quiet Noctua Fan. The result? Quiet…

NOTE: the picture links below expired, try this one: https://photos.app.goo.gl/8bkpPYffVUwuirY63

Fan: http://www.amazon.com/gp/product/B009NQLT0M?keywords=noctua%2040mm&qid=1454472310&ref_=sr_1_1&sr=8-1

Tools: Fan, screw driver, allen/hex wrenches that came with the Taz, tweezers, x-acto knife.

**Not responsible if you screw up. May void your warranty, blah blah, etc.

Incase photos are not showing up, here’s a link to them: http://postimg.org/gallery/zhii57ei/

Step 1: Disassemble the power supply (disconnect from power and ground yourself, obviously)

  • Remove 12 hex screws: 4 left, 4 right, 4 bottom. Pull off the black top cover.

  • Remove the 2 philips screws holding the fan as well as the small philips screw on the top right of the fan

  • Lift up the power supply to expose the screws on the left and right (silver part only, leave the black base on the table)
  • Remove ONLY the screws on the top rows: 3 on the right side, 2 on the left (looking at it from fan side).

  • Lift away the top case of the power supply to expose the PCB (here comes the fun part, wait for it…)

Step 2: Remove the old fan and install the new one

  • Use tweezers to remove the old fan from the connector. Please don’t yank it from the wire, it’s not the fan’s fault it’s loud.

  • Now there might be silicon holding the wire down. I just used my x-acto knife to cut away at both sides of the wire while pulling on the heat shrink part of the wire. DO NOT scrape away at the PCB or you’ll cut a trace.

  • If you bought the Noctua fan I linked above, connect the 3 to 2 pin adapter that was included (b/c Noctua is pure awesomeness)

  • **IMPORTANT STEP: The red and back wires on the Noctua connector need to be switched. Cut off the heatshrink from the end of the noctua fan connector adapter to make it easy. Remove the two wires from the JST connector and insert them in reverse order (look at the old fan for reference). Refer to the tutorial video (3:45) below for JST connectors
    JST tutorial: https://www.youtube.com/watch?v=kRvDgiX4Sk4

  • Insert the new fan into the connector and nicely route the cable. Use 2 of the rubber pins that were included with the fan to mount it into the case (pull it through the holes, takes some force).

  • TEST before putting it all back together (DO NOT touch the power supply when powered and exposed). It takes 5-10 minutes for the fan to kick during a print so be patient and don’t freak out like it did
  • ??? Boom!

Tested dozens of prints and did not have any issues. The old fan did not actively cool any components but was used for ventilation. Consider adding vibration dampers to your x and y steppers to cut the motor noise in half!

Stepper Dampers: http://www.ultibots.com/nema-17-damper-astrosyn-my17rmdamp/

Let me know if you have any questions at all.

Good luck!

EDIT: Currently working on replacing the case fan which is a 24V fan which is also insanely loud.

Modded my printer as well. (Buddy of mine took care of most of the labor). It is not as scary as it may seem, and it reeeeeeally helps. Also did the motor dampers. Guh, amazing.

Thx OP for posting this. Anyone else not seeing the images?

I had to try this and it worked! I can gladly say that the printer is much quieter. Hopefully you succeed in changing out the Rambo board fan to a quieter one. Keep us posted!

Can you not see any of the images? I can see them perfectly fine.

Most Of Them Are Broken For Me As well.

Very intresting, but also no images here. Only the word “Image”…

Lol…Just loaded the page in Internet Exploder and all images were ‘x’ but one loaded! Makes me feel like I’m ok 56K… Anyone here remember those days? Or am I aging myself? :laughing:

No problem! Not sure why the pictures are not showing up but here’s a link to them


Good luck

Isn’t the Power Supply 24 volts?

The fan you linked to is a 12 volt fan.

The power supply is 24V but the stock fan is rated at 12V which is connected to a 12v rail. The case fan is 24v though which makes it tricky to replace but stay tuned :wink:

I don’t suppose you know how much current that 12 volt rail is capable of putting out?

I needed a source of 12 volts for some fans and LED’s, so I added a 12 volt converter and mounted it to the outside of the control box. If I could get the 12 volts from the power supply, that would be much better.

I bought some 24 volt fans to replace the one in the control box but they were not any quieter so I didn’t bother. They weren’t Noctua fans thought cause, as I recall, I couldn’t find one.


I’ve got a Mini and the 80mm fan for the Rambo is 24V as well. I’m taking a gamble and getting a 12v Noctura and will look at putting a buck converter inline to drop it to 12V. I understand it’s a standard 2 wire fan so before doing it, I want to verify if it also puts out PWM. It’s hard to tell if that fan is off/on or variable as the unit prints. I don’t think 24V PWM will play well with a buck converter… So will do some testing first.

The voltage across the power supply fan pins is only 12 volts. The fan in the controller is 24V, but there is something more to it.

Yeah that’s exactly what I’m looking for lol. I don’t know the current rating of that rail unfortunately :frowning:

Maybe hook up a DMM in series with an led strip (or something that draws a good amount of current) and monitor the current draw. Maybe there’s a data sheet for the power supply?

I hear you man! I’m actually trying the same thing with a buck converter! When I hooked up my meter to that fan header, I was reading a duty cycle of about 100%. But if you look at the schematic for the Rambo, it’s a really weird circuit and I don’t quite understand it. If you measure the voltage across the fan headers you will get 12v. But if you use another ground, you get 24v from one of the pins…

So either a buck converter at that fan output or even from a 24v line (that way we can avoid and PWN issues). Not sure if the power loss from having a buck would cause other issues though.

Keep me posted though and I’ll do the same!



Stock fan should have markings as to the voltage input required… anyone check?

The stock fan in the controller box has a model number, when looking it up, it says 24v input.

What I’m going to test is tapping into the 24 Vcc that’s coming from the PSU and connecting the buck converter there. Just feel that the fan will be current hungry.

Another thing to think about is how the PWM with respond going through a switching regulator. The buck converter that I have has an LM2596.

What I’m going to test is tapping into the 24 Vcc that’s coming from the PSU

That’s what I did. But I attached a 5 Amp 12 volt converter so I can power more stuff (one of those encapsulated things).

I’m glad I decided to hook the wires up internally because while doing so, all of the wires in the screw connectors came out by themselves. They were barely tightened down. Loose wires to those power connectors could explain some of the issues many people complain of.


Yikes, that’s not good. Had the buck installed yesterday and fan was working fine. I also added some small heatsinks to the motor drivers to remove more heat off those.