I observed a problem with the work R52Hn - after mounting it in the RB433 or RB600 or RB433AH you can hear the quiet or loud squeak. This occurs only if R52Hn will be mounted on routerboard. What is important: RB is grounded, and power comes from the buffer power supply 24V / 55W. Has anyone had observed such effects?
We tried multiple power supplies before I wrote this post. Do you have any experience with such sound effects? Mainly we use the buffer power supply (high stability, large power and function of the UPS, of course).