Switch is being used in a portable production unit, so only used occasionally, not full-time service. On power up occasionally Power light stays on but SYS light stays dark.  When this happens DHCP doesn't work, web management is not available, and no ping response.  First time it happened I checked and there was a more recent firmware (20190516) so I installed this.  Now it happened again; tried a hardware reset using front panel reset button, but this didn't seem to work.  After multiple power cycles (at one point disconnecting all cables just in case this might make a difference) I finally saw the SYS light blinking, DHCP started again and was able to get web access.

I have two of these; the second switch has not been doing this.  Wondering if this switch needs to be RMA'd.

Is there anything else to try?  If not, what is the procedure to RMA a switch purchased through Amazon in France?