Dimension 8400 noise when cold

I've read a lot of articles here about 8400 fan noise, but
haven't seen the following symptoms described. Before I call
tech support (it's still under on-site warranty), I'd like
to get some theories about what the the problem is.

If the two-year-old 8400 has been in standby or power off
overnight in a room that's roughly 50F or colder, when it
starts there is a grinding/whirring noise that sounds like a
motor bearing beginning to fail. If I restart a few times
the noise does not disappear. But if i let the high-pitched
grinding continue for ten or fifteen minutes and then do a
power-on restart, the noise is gone and remains gone so long
as the computer is operating at normal room temperatures.
The 8400 is in use all day every day and the problem has
become more persistent over a two-month period.

Has anyone had the same symptoms with an 8400? Any idea what
the cause might be?

--David

"J David Ellis" <nospam@home.org> wrote in message
news:9OydnTR1zbEsi4nbnZ2dnUVZ_vumnZ2d@sti.net...
> I've read a lot of articles here about 8400 fan noise, but haven't seen
> the following symptoms described. Before I call tech support (it's still
> under on-site warranty), I'd like to get some theories about what the the
> problem is.
>
> If the two-year-old 8400 has been in standby or power off overnight in a
> room that's roughly 50F or colder, when it starts there is a
> grinding/whirring noise that sounds like a motor bearing beginning to
> fail. If I restart a few times the noise does not disappear. But if i let
> the high-pitched grinding continue for ten or fifteen minutes and then do
> a power-on restart, the noise is gone and remains gone so long as the
> computer is operating at normal room temperatures. The 8400 is in use all
> day every day and the problem has become more persistent over a two-month
> period.
>
> Has anyone had the same symptoms with an 8400? Any idea what the cause
> might be?
>
> --David


Open the case before you boot it next time (cold) and look at the fans
first:

CPU case fan (under the green shroud ), power supply fan (either can be
listened to via the back of the tower), or the video card fan if your card
has an active heatsink fan (you can try temporarily stopping this fan with a
pencil eraser or perhaps the plastic end of a pen).

Also look for cables rubbing the case fan or the video fan.

Beyond that, look/listen in the direction of your hard drives or
optical/CD/DVD drives......

Stew

Most likely the CPU fan. Actually, this symptom is pretty common.
Usually the noise will go away as the computer warms up (without
restarting). It could also be another fan or even a disk drive, but
when I've seen it, it's generally the CPU fan. Fortunately, it's a
generally easy fix (new fan).


J David Ellis wrote:
> I've read a lot of articles here about 8400 fan noise, but haven't seen
> the following symptoms described. Before I call tech support (it's still
> under on-site warranty), I'd like to get some theories about what the
> the problem is.
>
> If the two-year-old 8400 has been in standby or power off overnight in a
> room that's roughly 50F or colder, when it starts there is a
> grinding/whirring noise that sounds like a motor bearing beginning to
> fail. If I restart a few times the noise does not disappear. But if i
> let the high-pitched grinding continue for ten or fifteen minutes and
> then do a power-on restart, the noise is gone and remains gone so long
> as the computer is operating at normal room temperatures. The 8400 is in
> use all day every day and the problem has become more persistent over a
> two-month period.
>
> Has anyone had the same symptoms with an 8400? Any idea what the cause
> might be?
>
> --David

Stew and Barry, thank you very much for the prompt and
thoughtful replies.
--David

The Inspiron 6400 has a thermistor test that fails at around 50F
and below, that the computer takes as a temperature of 255C (very hot),
and it goes in full fan on, cache off, and slow crawl forward mode
until you reboot it. V12 Bios upgrade fixes it.

I mention it because, if there's a sensor test on the diagnostics
disk, you may find it fails it when cold ; the temperature matches
exactly what happens on the 6400.

Put it in a cold room and try the diagnostics out (just that one,
if it will let you).
--
Ron Hardin
rhhardin@mindspring.com

On the internet, nobody knows you're a jerk.

Those re the classic symtoms of a fan whose bearings have worn out. When the
fan first starts especially from a cold condition, the play in the bearings
cause the fan to wobble and vibrate. Quite often as you've discovered, once
the fan reaches operating temp and speed the wobble goes away and the fan
appears to run fine.


"J David Ellis" <nospam@home.org> wrote in message
news:9OydnTR1zbEsi4nbnZ2dnUVZ_vumnZ2d@sti.net...
> I've read a lot of articles here about 8400 fan noise, but haven't seen
> the following symptoms described. Before I call tech support (it's still
> under on-site warranty), I'd like to get some theories about what the the
> problem is.
>
> If the two-year-old 8400 has been in standby or power off overnight in a
> room that's roughly 50F or colder, when it starts there is a
> grinding/whirring noise that sounds like a motor bearing beginning to
> fail. If I restart a few times the noise does not disappear. But if i let
> the high-pitched grinding continue for ten or fifteen minutes and then do
> a power-on restart, the noise is gone and remains gone so long as the
> computer is operating at normal room temperatures. The 8400 is in use all
> day every day and the problem has become more persistent over a two-month
> period.
>
> Has anyone had the same symptoms with an 8400? Any idea what the cause
> might be?
>
> --David