Fan problem

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Hey guys,

today when i switched my PC on it came up with the screen "alert,
previous fan failure, press f1 to continue or f2 to setup"

Once i press f1 the PC seems to be working fine but I called Dell up
just to check what was happening. They made me open up the PC and
unplug the fan and plug it back again and it still didnt work. They
then asked if a green light was 'on' on the motherboard...which it
wasnt. The guy came to the conclusion that either my processor fan has
gone or the motherboard has gone.

He went on to say that the processor fan is fairly easy to replace
whereas the motherboard is expensive and a long procedure. I'm going
to buy antoher fan to check if that works.

But how important is a processor fan and is it ok to use the PC
without it?...right now i have a regular desk fan blowing in at the
back of the this ok for a temporary solution?

I hope its only the fan problem since the motherboard will cost a lot

Anyone else had this problem before? any help will be greatly

PC Specs: Dell dimension 8250, 2.8ghz P4 - i dont have any warranty

Re: Fan problem

Thanks mate, I'll look into the DC power supply to check the fan. What
about have a normal desk fan blowing in to the back as a temporary

Re: Fan problem

Good grief no, never use a CPU without a fan, a CPU will last about 10
seconds without one.... the power used by a CPU does vary according to
type will be around 50 Watts or so.

Does the fan looked clogged with dust, this could stop it rotating,
does the fan blades turn easily by hand or does it feel sticky...?

One way to check a fan is to use a 12 Volt power supply.... a  battery
or even a wall wort will do for this set between 9 to 12 Volts, this
must be DC of course and you must remember to get the Positive and
Negative wires the correct way round.

There could be other reasons... the fan is not turning,  try using the
CPU without a fan and you'll need a new CPU thats for sure.


Re: Fan problem

On Sat, 20 Jan 2007 02:58:04 -0000, no@spam.invalid (azcorp)

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At that point, the prudent thing to do is immediately go to
the back of the system and check whether the rear fan is
exhausting, if you feel active air coming out or hear it
spinning reasonably.

This appears to be your system, it looks to have the typical
passive 'sink and rear exhaust duct that many of Dell's use,
is this correct?

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I would not put much weight in the suggestion about the
green light, it is not likely you need to replace the
motherboard and frankly, even in the remote chance the board
fan controller had failed, I would just run a fan straight
from the PSU at constant speed ($5 fan replacement) before
spending an arm and a leg on a motherboard - I'd sooner
upgrade to an aftermarket board with a new CPU too for the
performance increase before paying a premium for same thing.

What probably happened is your board bios isn't very good at
detecting very low fan RPM.  That triggered an error, so
what remains is to figure out if the fan every spins too
slow or not at all when it should (it may be that it doesn't
"need" to spin when the system is running cool, and if your
ambient room temps are lower now than at other times of
year, that would account for the CPU being cooler and the
fan spinning slower as a result, or even stopping from
spinning, BUT if you did something with the system that put
the CPU under fair load to raise it's temp, it is then
expected (and necessary) that the fan start spinning and
ramp up in speed as expected to keep CPU cool enough.

So I'm suggesting that you don't have direct evidence of a
problem with your cooling subsystem, it may be doing what it
was designed to do except that the board bios can't resolve
what was happening, the crude artificial logic for the fan
RPM didn't have enough forethought put into it to account
for this scenario.

On the other hand, you could actually have that fan failing,
it is not too uncommon a fault on some Dells depending on
what brand they used at that moment (they have multiple

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Ok, but what does  Dell charge for the fan?  It's probably
quite overpriced too, but hunting down what you need on the
internet could take a bit of time instead so it's the
age-old TIME VS MONEY factor all over again.

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No, that is not an acceptible solution, that fan is
manditory in your system.  Some systems' rear exhaust fans
only help to keep the chassis better ventilated but on yours
(and many OEM systems) that fan is directly responsible for
pulling air through a duct over the CPU heatsink, thus the
primary cooling for the CPU.

IF you were really desperate to use the system AND the fan
had really failed (I mean it doesn't start spinning after
the CPU starts getting hotter) and system uptime was more
important than anything else, then (and only then) (and only
if you didn't have another (92mm?) spare fan you could swap
into it's place (which BTW, you might be able to find at any
reasonably stocked computer shop even if not the right
speed, even if not able to be powered by the motherboard (4
pin?) fan plug, THEN without these options the next best
option would be to remove the original fan and duct, and
point an external fan directly at the heatsink on the CPU.

If you were trying to cooling it with an external fan you
would also want to avoid doing anything that subjects it to
a continuous full load unless you are sure it's staying cool
enough, as a mostly idle CPU (as with typical internet
browsing, office uses, etc) produces far less heat, wouldn't
require as much airflow or as efficient a heated air removal
as it otherwise would.

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If it is a sleeve bearing fan you might be able to put a
drop or two of heavy oil in and keep it running for quite a
while, IF it's even a fan problem (as mentioned above,
colder room might result in low or no fan RPM till it warms

Re: Fan problem

azcorp wrote:
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Not unless you want to replace the processor, too. Just leave it off
until you get your new fan.

Anyway: here's the service manuals. /

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