paulca

Faulty switch in isolation. Only DC power connected. Test 1. Switch booted to solid green light. Connect 30cm patch between ports 9 and 10. Two blue lights for a few seconds. Then Port 10 light goes dark. A few seconds later port 9 goes dark, port 10 flashes blue once and both ports become disabled with no lights. Test 2.…

Your diagram is correct. Except the MG105 is on port 10, the port that is the problem. Switch 2 - port 10. Only ports 12 are linked with a Cu 30cm DAC cable. Port 11 is free. Connected Device: Is the device connected to port 10 of Switch 1 a Zyxel MG-105 or another device? Have you tried swapping out the connected device…