Out of the blue, one of my tried and true 10/100 16 port Netgear JFS516 switches quit. I replaced it and set it aside. Eventually I opened it up to see if I could see any obvious reason why it died. I had observed that none of the LEDs were lit and suspected the power supply may have died. These switches have an internal power supply — they do not use a wall-wart.
I opened it up and found that, on the power supply board, one of the electrolytic capacitors seemed to have a bulge on the top of its can. A nearby diode seemed to be cracked and there also was some dark brown discoloration from overheating.
I replaced the cap and the diode and all was well! Getting the diode out required completely demolishing the diode. The cap was easier.
Notes: cap was 2200uF, 16v; dode was 1N4731. Be sure to note band on diode and polarity of cap.
I also have a JFS516V2 switch. You’d think they were idendical…but they’re not!