Odd fan noise with C2950, normal?

[InlineFive]

Hey everyone,

I just received a Catalyst WS-C2950-24 today but the fan doesn't sound quite right to me. While it has the normal "wooshing" air noise it also has a very loud "harsh" vibration noise too. Almost like it's not quite secured inside the case.

Here is my question, depending on my financial situation in two-three months I might buy a SmartNET contract for this but I don't want to void any chance of acquiring one by opening the chassis to take a look at the fan (and possibly adding some rubber insulation around the fan to stop vibrations).

Any advice?

Thanks!

I5

 

[jlazzaro]

i say you mod the hell out of it and put in super silent 4db fans ;o

seriously, not sure why type of fans the 2950 uses. it could be loose, or maybe just a bad bearing. i would crack it open regardless...why buy smartnet on lab equipment.

ps ygpm

 

[InlineFive]

Thanks for the PM, working hard or hardly working?

I will crack it open and check the fan. Might order a new one from Cisco.

 

[p0lar]

Originally posted by: InlineFive
Thanks for the PM, working hard or hardly working?

I will crack it open and check the fan. Might order a new one from Cisco.

1) You won't void smartnet
2) it's ultra easy to replace and should use a standard 3-pin connector -- I've actually removed fans from lab elements that were air-conditioned before with no problems whatsoever (i.e. C2691, unnecessarily loud!) except for the complaint every so often on the console and some show env warnings.

They're generic fans, either way, so if you can find one that is silent, it will work fine. Funny story, I actually used a Cisco fan header to charge a digital camera when the crazy voltage popped my camera charger in the middle east. Back to your regularly scheduled programming!

 

[InlineFive]

Hmm, I might consider going the quieter fan route. The inside temp here is around 70-80f and the device will probably be under 0.60% load so that should be okay.

Edit: One question. Did you actually try an off-the-shelf 3-pin fan with one of these? It appears as though the 5v and Ground wires are swapped (if the color codings are the same). Easy to splice together, but still curious.

 

[p0lar]

Originally posted by: InlineFive
Hmm, I might consider going the quieter fan route. The inside temp here is around 70-80f and the device will probably be under 0.60% load so that should be okay.

Edit: One question. Did you actually try an off-the-shelf 3-pin fan with one of these? It appears as though the 5v and Ground wires are swapped (if the color codings are the same). Easy to splice together, but still curious.

Well, on a DC-based fan, reversing the polarity will reverse the direction usually, unless it has a diode to prevent such things. At that point, you could just turn the fan around and let it push the other direction, I suspect. Or, you could interchange the pins inside the connector housing and do it the right way. I don't have a 2950 on-hand here in my home lab at the moment, but I do have a few 3550s and a 3750 I will poke my head into when I get a free minute.

 

[InlineFive]

Originally posted by: p0lar

Originally posted by: InlineFive
Hmm, I might consider going the quieter fan route. The inside temp here is around 70-80f and the device will probably be under 0.60% load so that should be okay.

Edit: One question. Did you actually try an off-the-shelf 3-pin fan with one of these? It appears as though the 5v and Ground wires are swapped (if the color codings are the same). Easy to splice together, but still curious.

Well, on a DC-based fan, reversing the polarity will reverse the direction usually, unless it has a diode to prevent such things. At that point, you could just turn the fan around and let it push the other direction, I suspect. Or, you could interchange the pins inside the connector housing and do it the right way. I don't have a 2950 on-hand here in my home lab at the moment, but I do have a few 3550s and a 3750 I will poke my head into when I get a free minute.

Well my new Sunon KDE1204PVK3 arrived so I spliced the wires, added some ultra-ghetto ducting inside of the switch and it all works! The power light is green so the switch is happy again now that it's got an RPM signal.

Plus it's quieter too. Heehee.

 

[p0lar]

Originally posted by: InlineFive
Well my new Sunon KDE1204PVK3 arrived so I spliced the wires, added some ultra-ghetto ducting inside of the switch and it all works! The power light is green so the switch is happy again now that it's got an RPM signal.

Plus it's quieter too. Heehee.

Pics or ban!

P.S. Nice job! :beer:

 

[InlineFive]

Originally posted by: p0lar

Originally posted by: InlineFive
Well my new Sunon KDE1204PVK3 arrived so I spliced the wires, added some ultra-ghetto ducting inside of the switch and it all works! The power light is green so the switch is happy again now that it's got an RPM signal.

Plus it's quieter too. Heehee.

Pics or ban!

P.S. Nice job! :beer:

It's nothing impressive, what I basically did was block a portion of the large empty space at the rear of the switch. Since the KDE1204PVK3 only pulls 66% of the stock KDE1204PVKX airflow I wanted to ensure that more air would travel over the processor and memory before being exhausted.

I will post pictures later.