There are many issues related to the fan reliability on D-Link switches.
http://www.amazon.com/D-Link-24-Port-Rackmountable-Gigabit-Switch/product-reviews/B0002TPFTAI own the DGS 1024D and it died about 1.5 years into service. The network was down, I went in and looked at the switch (through the smoke-filled large closet) and ALL of the lights were lit up. The case was extremely hot and left a burn mark on the mounting board behind the unit.
I unplugged it and let the smoke clear, then plugged it back in. Nothing. No lights, fan, etc - zero.
The fan had been making a rattling noise for about 3 weeks prior to the failure so I guess it was in the process of failing. When that happened I think the unit overheated and probably would burnt my house down had I been on one of my business trips.
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I've owned the DL switches, a 4 port, 8 port (desktop models) and this 24 port unit. All three of them have failed with within 2 years of service. I would strongly advise completely unplugging the unit and putting it away if the fan makes any noise whatsoever. I've mailed the CPSC a letter about this but have yet to get a reply.
Two other 24 port switches (from a diff mfg) have all been in operation for more than 3 years without a hiccup. D-Link really needs to look into this problem since it appears to be widespread.
I have not yet sent it back for repair since I'm afraid the refurbished/replacement unit would probably have the same issue over time and maybe do the same thing.
Don't get me wrong, the units are very fast and work great WHEN they are working, but seem to fail at the most inopportune time
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