Hi Candlestorm,
to be honest, I didn't even realise that there was a fan "rattling". I never noticed the fan during setup and the first few days of use *quiet environment* and I can usually hear the quietest frequencies. The FWA510 is on the table where I work. Unfortunately, I'm no longer on site, so I can't check it again live.
Hope this helps.
I can't find any reference to a fan either:
https://www.zyxel.com/ch...VG