Replacing noisy stock fans on a HP 1920-24G-PoE+ Switch (JG925A)
I have recently been researching VLANs for my home network. These will be used to split up my network devices into their own logical network, such as IP Cams, IoT devices and Guest WiFi.
My current PoE switch was unmanaged, I had to replace this with a managed version. I already had a HP ProCurve non-PoE switch, I liked it; so I went hunting for a HP branded PoE switch on eBay.
My main requirements were that it was PoE+ capable, Managed, Rack Mountable and had a web-ui (I found this to more intuitive than console).
I found a used HP 1920-24G-PoE+ (180W) Switch, model ID: JG925A for £90. Not bad.
This switch was going to be housed in a rack; in a cupboard accessed from my lounge room, so I had to replace the fans with some quieter versions as the fan noise could be heard even when the cupboard door was closed.
I ordered two Noctua NF-A4x20 PWM fans from Amazon, these were the quietest fans I could find, and I had used Noctuas in other devices with great success.
It didn’t matter these new fans were PWM variants, as I wouldn’t be using the PWM wire.
Note: before opening the case of the switch, be sure you’re comfortable with handling electronics. There are PSU capacitors inside which could give a deadly shock if touched.
I installed these fans by snipping the cable of the original fans and of the new Noctuas. Then used some ‘clip-down’ style connectors from eBay. These connectors are great, they don’t crimp the wires and allow the fans to be removed in more less destructive way.
The fans were wired like this:
- Original fan cable Red wire > Noctua Yellow wire
- Original fan cable White and Black wires > Noctua Black wire
- Blue and Yellow Noctua wires are left unconnected.
The White and Black wires were combined to prevent the switch showing errors regarding failed fans. I’m guessing because these Noctuas have a lower RPM speed than the original stock fans, the switch’s self-diagnostics thinks the fans had failed.
I understand the Noctua fans are not as powerful as the stock varient, but this should not cause as issue for me as I am only using about 4 PoE devices. If you’re using more then you may want to monitor the temperatures.
Overall this was a good modification; the switch is now much quieter.