I wanted to create a post to help anyone looking for replacement (quieter!) fans for the XS728T switch. While the XS716T and XS708T are easy, with direct Noctua swap ins, the XS728T is an entirely different beast. Noctua fans DO NOT WORK with the XS728T due to them requiring a higher starting voltage than this switch can provide. They spin up for half a second and then stop. Fans that have a lower starting voltage, such as the Arctic S4028-6K, work great!https://www.arctic.de/en/S4028-6K/ACFAN00185A IMPORTANT: The fan pin configuration of the XS728T is non-standard. If you connect a fan without swapping the pins around you WILL BURN IT OUT. You must SWAP the PINs of a standard fan as follows:PIN1 (Ground - *Black) --> PIN3PIN2 (Power +12V *Red) --> PIN1PIN3 (RPM Speed Signal *Green or Yellow) --> PIN2PIN4 (PWM Control *Blue) can be ignored as it is not used here.Image of original fan with the required pin configuration attached.

The fans linked in my fist post may well be a little under powered for the XS728T!These are a better option after all.ARCTIC S4028-15Khttps://www.arctic.de/en/S4028-15K/ACFAN00264A

Happy you discovered yet another switch fan replacement - which does at least reliably spin-up at the low start-up voltage. Here again, the proposed replacement does not even deliver half of the design expected cooling (airflow). Lower max nominal RPM, ... of course, this fan must be quieter then... Here the OEM fan data (Delta Fan AFB0412SHB) and OEM installed AFB0412SHB fan data sheet. The never ending dream and illusion...

schumaku I've run a XS708T and two XS716T switches, fully populated at 10G, for years and years now using low airflow Noctuas and not had any throttling or other issues. GUI has always reported temps well within tolerances on all 3 units.I don't think anyone actually cares what the 'expected airflow' is when there is no impact to using much quieter fans.

I am using an xs728t in a homelab environment (access to plenty of climate controlled air). In order to mitigate the INCREDIBLY loud fan noise from this thing, I went looking online for fan replacement options and found this post. I bought both the arctic 6k and 15k fans and appropriately made the pin modifications in the OP. I started with one of the 15k models and noticed that they didn't want to spin up at all. My best guess is that they didn't work because of requiring a higher starting voltage than the switch is giving (which of course is the problem with the noctua replacements) - I tried the 6k versions and they spin up just fine. they don't move a whole lot of air compared to the stock delta fans, but they still don't spin up to full blast while managing to keep the switch at a still pretty toasty but I think ok ~70c (please let me know if i'm wrong), HOWEVER, the switch's fan error light is on and in the web ui, it tells me that each of the fans is intermittently not functioning (each fan will say not functioning at some time or another and eventually say that it's normal again). 1. Is 70c an ok temp for these switches (or am I slowly killing my switch doing this)?2. is there a more appropriate fan replacement that is quiet, moves adequate air, and doesn't cause the switch to say that the fan isn't functioning? I have seen various places on amazon and ebay list that they have fans that work well as replacements for the xs728t (named specifically by model) that they guarantee to be compatible (i.e. not flag the error light / say non-functioning in the web ui) as well as being quieter, but none of them that I've looked at mention a fan model number and my attempts to reach out have either been answered by "we're a dropshipping company, I have no idea what fan this is" or in most cases with absolutely no reply at all (very frustrating). If any one has any information on alternatives, I would be very much interested. Thank you! And thank you Squuiid for the op with the proper pinout changes.

Here is the output from the web UI illustrating my previous post. Please note that the fan statuses change seemingly at random with every refresh of the page. sometimes they all show "normal", sometimes all "not functioning" and typically a mix of the two. Also of note, the stock delta fans have always worked and have never thrown an error. I'm also not sure exactly what's being detected as far as the status is concerned (my best guess is that it varies the voltage and that it sends back a tachometer signal and the fan isn't spinning fast enough for the software threshold?) I'm not sure if I should just use it the way I have it and call it fine, or if I should be worried and seeking of other options.

XS728T fan replacement options | NETGEAR Communities

18 Replies

schumaku
Guru
Jul 07, 2023
Happy you discovered yet another switch fan replacement - which does at least reliably spin-up at the low start-up voltage.

Here again, the proposed replacement does not even deliver half of the design expected cooling (airflow). Lower max nominal RPM, ... of course, this fan must be quieter then...

Here the OEM fan data (Delta Fan AFB0412SHB) and OEM installed AFB0412SHB fan data sheet.

The never ending dream and illusion...
- Squuiid
  Luminary
  Jul 07, 2023
  schumaku I've run a XS708T and two XS716T switches, fully populated at 10G, for years and years now using low airflow Noctuas and not had any throttling or other issues. GUI has always reported temps well within tolerances on all 3 units.
  
  I don't think anyone actually cares what the 'expected airflow' is when there is no impact to using much quieter fans.
  - Squuiid
    Luminary
    Jul 08, 2023
    The fans linked in my fist post may well be a little under powered for the XS728T!
    These are a better option after all.
    ARCTIC S4028-15K
    https://www.arctic.de/en/S4028-15K/ACFAN00264A
FURRYe38
Guru
Jan 12, 2024
For a more non invasive solution, I went with a small fan, 2 screws and nuts, small RE magnets and a 3-5v USB power supply or any USB power supply will do. Attach to either side of the switch and push or pull air flow.
- iieeann
  Aspirant
  Jan 13, 2024
  That may work with 5V fan. My fans are 12V... Speed control is important for me because the switch is at the bed room. Now the fan noise is not audible after 1.5m.
  Before i modified the fans, the switch had been running fanless for almost a month, no problem at all and the casing was not hot.
  The switch was put vertically, fan at the bottom pushing out the air. Air inlet side on the top is covered with magnetic dust mesh.
  Duest mesh
  - FURRYe38
    Guru
    Jan 14, 2024
    Just wondering why you would have such a noisey device in the bedroom?
    
    I'd put in a non managed fanless small switch in the bed room and place this one else where if it was me. But to each his own.
BrianL
NETGEAR Moderator
Jan 17, 2024
Hi Cpgeek,

Please do check our warranty terms and conditions from this page https://www.netgear.com/about/warranty/ regarding modifications.

Kind regards,