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Inside WRVS4400N

Discussion in 'Cisco Small Business Routers and VPN Solutions' started by Dacsman, Jan 17, 2008.

  1. Dacsman

    Dacsman LI Guru Member

    Whining is driving me crazy and I want to see what it may be. After opening the unit and plugging it back in the unit was silent. Anyway I took two pictures of the inside for viewing. For some reason the heat sink is offset because of the shield.

    Attached Files:

  2. DocLarge

    DocLarge Super Moderator Staff Member Member

    Any idea where the whining was coming from?
  3. Dacsman

    Dacsman LI Guru Member

    I had spoke too soon yesterday, after having the router plugged in for a bit the whining started as I had the board to my ear it sounds like it is coming somewhere between the two star chips. Almost sounds like it is coming right from the board. I am going to get some small plastic tubing and use it as a stethoscope to try to pinpoint the whine.
  4. GalacticLink

    GalacticLink LI Guru Member

    Mine has always had that hi pitched wine. It is most likely part of the first batch, as I was fighting to get one shortly after they were released. The only time I hear it is if I use even 1 gigabit connection. If I force everything to 100 wine goes away immediately. Sometimes I don't notice it for a minute if router has been off long enough to be cold, but I have noticed it right away as well. Lucky for me my 4400 is in a room that only with a power outage would you ever really hear it without getting right up next to it. Has nothing to do with type of power input as I have seen others mention. Plugged in wall or into its dedicated, voltage regulated, filtered UPS makes no difference.

    Hope you find out which chip it's coming from, since the company does not care. After seeing that heatsink out of place you are making me want to check mine as well now, before summer comes. :(

    The only other thing that annoys me about the unit since last firmware is how long it often takes to load the gui webpages completely when configuring.
  5. Dacsman

    Dacsman LI Guru Member

    From what I can see and hear the whine is coming from the Star 9109 or the GB switch. With the unit open and running you can barley hear the whine after closing the unit and it heats up is where it becomes much noisier, open it and within a few minutes the noise disappears to almost nothing. I am suspecting a heat issue and not enough proper ventilation due to all the shielding and the copper blanket under the board. I did not take a picture but the Vitesse gets hot enough where it actually discolored the underside of the board. Before closing the unit I remounted the heat sink on the cpu for the switch and had to cut away some of the shielding in order for it to clear. As for this unit it is back together and working, what I will do with it next?
  6. Aviator256

    Aviator256 LI Guru Member

    WRVS4400N Temperature Related Noise Confirmed

    I tried a few things:

    Although the ambient temperature specification for the unit is much higher, the noise can become a problem when the unit is flat with an ambient temperature above 100 Deg F. At this point, the surface temperature rises from 105 Deg F to 115 Def F and the noise begins to show up. If the unit is in an enclosuer, ensure the ambient temperature above the unit (near the inside top of the enclosure) is below 100 Deg F. If it is above 100 Deg F, add some holes or a fan near the top rear of the enclosure and the bottom rear of the enclosure to create a draft. It also helps to place the unit on its side (tall - antennas on top). With the same ambient temperature, the center surface temperature drops by about 5 Deg F and during my testing the noise was eliminated.


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