Re: 3com 2824-sfp
Alot of the times their is not a physical reset switch on higher end switches, and instead you need to do some complex fun thing. I'm guessing you already checked the manual like me, and it does not mention any reset procedures besides the gui.
Three things to try.
1: Reset pin, easiest thing to try. Likely doesn't exist though.
2: Console / Serial port on switch. Look for a serial or RJ45 port. If it's RJ45, it will be a single port likely on the back, isolated from any other ports. If theirs one of these, i'll help you figure out how to reset it.
3: Connecting port 1 and 2 with a cable. Do this, power off the switch for 30 seconds, power it on for 30 seconds, than disconnect cables (and possibly power cycle it again). Likely wont work, but worth a shot.