I have a D-Link GDS-2205 switch that I picked up cheaply. It turned out it was cheap because it didn’t work. But I thought I’d try to open it and look for bulging capacitors, since that’s a common problem with low-end network equipment.
Opening these boxes is tricky, but not impossible.
There are two Philips-head screws hidden beneath the rubber feet on the back of the unit. They come off fairly easily because there isn’t a lot of surface area for the adhesive to stick to.
After removing those two screws, flip the switch back over.
The top portion of the case has some tabs holding it together. The easiest tabs to reach are on the sides, right where the silver portion angles slightly upward. Insert a small standard/slotted/flat-blade screwdriver into the lip between the black top and the silver sides where they start to angle and pry gently. Once that tab releases, the top opens easily.
Unfortunately once I got my case open, I couldn’t find any obvious problems. But if you’re faced with one that stopped working, it doesn’t cost anything to pop it open and take a look. If you see one or more capacitors that are bulging or have burst and discharged a strange looking liquid that vaguely resembles coffee, you’ve found your problem.