How Much Fan Noise is Too Much?

Greetings to all. I've had my Dimension 4600, P4-2.8 GHz with Nvidia 5200 128MB
video card for a little over a month now. Right out of the box I thought it was
noisy, at least compared to my year old 4550 with P4-2.4 GHz with Nvidia MX420
64 MB video card. I would describe the noise as a dull buzz or hum. Mind you,
it's not LOUD but compared to the 4550 it does make noise. My parents and a
friend also bought a 4600 at the same time I did (one day sale) and their
machines are whisper quiet, comparable to my 4550.

I always assumed the noise was due to a cooling fan on the Nvidia 5200 video
card, and didn't give it much thought, but last night I felt the side of the
computer case and could feel vibrations. This led me to believe it was not the
video card fan. In fact, after opening up the case and looking around, it
appears the FX5200 video card does not have a cooling fan.

With the side of the case removed and the computer laying on its side, I
powered it up. After it spooled up I put the machine in hibernation mode. Then
I lifted the green fan housing that goes over the CPU so I could eyeball the
fan and bumped the mouse to get it out of hibernation mode. The noise is still
there but not as loud. I replaced the fan housing and noticed that if I pressed
my finger on it, I could alter the pitch of the noise slightly. I believe I've
isolated the source of the noise. My suspicions are that the fan has a
vibration in it that is causing the noise I hear. Somehow this vibration gets
passed along through the fan housing and into the case causing the vibration I
can feel with my fingertips. I note that there is no vibration to be felt in my
4550 (the case has plastic sides which might help it to be quieter than my new
4600) or my parent's 4600, which also isn't as loud as mine. When the side of
the case is replaced the noise the CPU fan makes gets louder and more
distinctive.

My fear is that because of the vibrations, the fan will prematurely wear out
(while out of warranty too, I presume!) and I'll have to replace it. My
question is: Is this a warranty repair? How much fan noise is too much noise?
Will Dell replace it without question or will they try to make my qualify how
loud it is? Will they deny it's a warranty item?

 

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Possible but highly unlikely. The fan would have to run greatly out of
balance for the bearings to wear quickly. Smoking or a very dusty
environment has a much harsher effect.

It is indeed.

How much fan noise is too much noise?

Very subjective. One users noise is another users whisper quiet. If it
bothers you then it is too much noise. Most boxes are never completely quiet
but it should not be annoying either.

No...they have replaced fans for me before with no questions asked. Simply
explain that the noise is at the level which makes it impossible to ignore.
Describe it as a most definite noise with the fan under the shroud.

Will they deny it's a warranty item?

Any hardware problem including a noisy fan should be warranty with no
questions asked. This is a far simpler warranty claim to validate than for
instance a bad video card. Noise is noise...simple as that.

John O.

 

Alan S. Wales wrote:

It's definately covered by warranty. I got a replacement fan when the
first fan got too noisy. Now the second fan is starting to exhibit
noise. I am still under warranty, might get another one!

Buck

 

| With the side of the case removed and the computer laying on its side, I
| powered it up. After it spooled up I put the machine in hibernation mode.
Then
| I lifted the green fan housing that goes over the CPU so I could eyeball
the
| fan and bumped the mouse to get it out of hibernation mode. The noise is
still
| there but not as loud. I replaced the fan housing and noticed that if I
pressed
| my finger on it, I could alter the pitch of the noise slightly. I believe
I've
| isolated the source of the noise. My suspicions are that the fan has a
| vibration in it that is causing the noise I hear. Somehow this vibration
gets
| passed along through the fan housing and into the case causing the
vibration I
| can feel with my fingertips. I note that there is no vibration to be felt
in my
| 4550 (the case has plastic sides which might help it to be quieter than my
new
| 4600) or my parent's 4600, which also isn't as loud as mine. When the side
of
| the case is replaced the noise the CPU fan makes gets louder and more
| distinctive.


Great Post! My 8300 (I've only had it a few weeks), is exhibiting much of
the same symptoms right out of the box. I can actually feel the case
vibrating. Personally, I do not think the source of the noise is the fan,
but rather the fan housing. Sometimes a swift tap on the side of the case,
or moving the entire CPU just slightly will quiet it, but eventually the
sound and vibration returns. I agree with your observation - the fan
mechanism itself passes the vibration onto the housing.

It doesn't help that evidently in shipping, my CPU seemed to have been
tossed around a bit. While the case was intact (no scratches or
misalignment), all the cards were loose on arrival and had to be reseated.
That green clip that holds down the cards and slot covers was completely
unhinged (remember the days when the cards were actually attached with a
screw!?), and one of the card slot covers had been completely dislodged and
was floating around inside the case. Fortunately, it didn't appear to have
damaged any components.

Although I did a cursory look and listen at the fan housing with the case
open, I haven't really taken the time to pull it all apart. I need to do
this.

 

In both the 43XX-83XX series and 23XX-24XX-46XX (non-C) series, the problem
is usually the hinged shroud on the assembly (this assumes that the assy. is
properly seated and locked to the chassis, and that the fan itself isn't
failing).

The early 43XX (hinged) chassis had a method of dampening the shroud when
the case was closed; there was a small piece of adhesive foam (about 3.4" X
1.0" rectangular) placed horizontally and externally on the highest point of
the shroud (when in the down/locked position). The idea was apparently that
when the case was closed, it came in contact with the foam on the shroud,
which held the shroud down firmly and with dampening. Such adhesive foam
can be purchased at most any discount or hardware store and experimented
with. I have no idea when or why that was abandoned.

The 23 24 46XX fan assy. is not nearly so robust, meaning, the plastic on
the shroud hinges themselves are 1) very thin and prone to be broken, and 2)
are very loose even when intact - begging to vibrate/buzz/or humm. Though
I've not tried it, I suspect that could be reduced, if not eliminated, by
treating the contact areas between the shroud and fan housing when the
shroud is down/locked/closed. The shroud on this assy. can actually be
removed by swinging it all the way upward, aligning with the tabs on the
assy, then gently pulling each side off. This would confirm or eliminate the
shroud as the source of the noise.


Stew

 

"S.Lewis"

Excellent advice. I will see if it is the fan shroud or the fan itself that is
making the noise and take action as appropriate. I already have some of those
spongey-foam adhesive squares and will try one of those if the noise turns out
to be the shroud. If it's the shroud's hinge area, I'll MacGvyver something to
take care of that. If it's the fan, I'll try out Dell Customer Support and see
what happens.

 

I'm definitely taking notes on this thread.

I wonder if the fins of the CPU heat sink also contribute a 'hum'. Case in
point: On a recent expedition to blow dust out of my Dimension 4500, I
lifted the green plastic shroud covering the processor and blew some air
into the area. The heat sink fins 'hummed' when I did this.

Rocky

 

snip

Hmm. Slightly aside, but my 5100 fan comes on WAY more than my old 4000
ever did. Any download will keep the fan on for the duration. ideas?

 

<snip>

Rocky,

I doubt that the heatsink fins or even clips would be a part of the noise.


Stew

 

"S.Lewis"

I doubt it too, but I suppose if the air flow through the heat sink fins is
sufficient, the fins could start vibrating. I'm guessing that is what happened
when he blasted them with the air gun. I don't think that the CPU fan could
create that type of airflow, however.

 

I believe you are both correct. I blew directly down onto the fins - the fan
draws air across horizontally.

Rocky

 

The biggest potential for fan noise with these assemblies is usually the
shroud fit/mount to the assembly, or the entire assembly mount/fit to the
chassis (or a failing fan).

The fans themselves ride/float upon rubber bushings within the assembly.

Some of these systems have a flexible, polished metal heatsink while most
have aluminum with static fins.


Settw