# Dell Dimension 3000 - CPU fan go Wild!



## Compiler (Oct 11, 2006)

This is kind of a new one for me....

One of my clients Dells, a Dimension 3000 (P4 3.0ghz / 512mb/ standard PCI intel board) has recently gotten very loud with its COOLING fan spinning way to fast. This happens with the system being IDLE but seems to be worse with a light-load of work being used.

As with pretty much most Dells - the CPU temp/ FAN RPM monitors are blocked from end users and not displayed in BIOS. If I put my hand over part of the rear-air vent - the FAN will spin EVEN FASTER.

How these Dells are set up (in case ya don't know) The CPU Cooler fan is NOT attached to the CPU heat-sink. Dells uses a "air scoop" that covers the Heat-sink and the rear-case fan... so it SUCKS in cooler air through the heat sink and out the back.

So, this kind of tells me that when I am covering the rear air-vent, the CPU could be getting hotter which is telling the BIOS/Mobo to speed up the fan to cool the CPU. The inside of the case IS CLEAN - nothing blocking the air-ways. The Heat-sink is clean as well.

The PC is out of warranty - and typical Dell - the BIOS has no options or information to help. My theory is that the mobo maybe confused and is running the fan faster than it needs to be.... Or if its over-heating, why? The office is not hot, even with the cover off, it makes no difference... if the mobo is shot, it sure isn't worth repairing.

Any ideas?


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## xtreampb (Jan 30, 2007)

can you plug the fan into another plug on the mobo.
im not farmiliar with dells or with spelling.


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## Carmichael-07 (Apr 2, 2007)

My Dell computer did that also, sounds like a broken lawnmower. I opened it up to find a fair bit off dust inside, I used a can off pressurised air to get rid off the dust, and after that the noise was reduced. However you aid the inside was clean, once mine was clean the was still a slight noise, i put a support under one side as the tower was wobbly and the noise stopped, maybe the tower is lobsided like mine was.


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## bernardus (Oct 13, 2004)

With Aida 32 or Everest you could screen the sensors of heating or temperature.
It is either the fan which doesn't send out the signal from the speeddetector or your motherboard is translating the data incorrect. With some PC's you could monitor these info and adjust it with software settings. Is the cable all right and fitted in it's place?

http://attachments.techguy.org/attachment.php?attachmentid=102270&stc=1&d=1175599856


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## win2kpro (Jul 19, 2005)

Personally, I don't like Dell's passive heatsink cooling arrangement, however processor overheating is rare. The processor has an on die thermal diode that will shut down the processor @ 135c.

3 things I would check are;

(1) Remove the front cover and check that the air intake is not obstructed.
(2) Remove the heatsink, clean the heatsink and processor and reseat the heatsink with new thermal compound.
(3) Check the fan orientation and make sure the fan is pulling air through the case an exhausting to the rear of the case, and not pulling air from the rear to front.

Here are the thermal guidelines for a P4, socket 478;

http://www.intel.com/design/pentium4/guides/24988903.pdf


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## Compiler (Oct 11, 2006)

bernardus said:


> With Aida 32 or Everest you could screen the sensors of heating or temperature.
> It is either the fan which doesn't send out the signal from the speeddetector or your motherboard is translating the data incorrect. With some PC's you could monitor these info and adjust it with software settings. Is the cable all right and fitted in it's place?
> 
> http://attachments.techguy.org/attachment.php?attachmentid=102270&stc=1&d=1175599856


Yeah - AIDA32 is no longer available for free (or everest for that matter) - which was a great tool for such things.

Today's closest replacement (legit) is PC Wizard - and its 100% free:
http://www.cpuid.com/pcwizard.php And its pretty good too.

Anyways - er... as I stated - DELL doesn't allow monitoring of its sensors (RPM and CPU & mobo temps) - we KNOW the chipset and CPU supports these. But this is how Dell does these things. AIDA/Everest don't work.


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## Compiler (Oct 11, 2006)

Win2KPro...

PC is clean. Fan is in proper position. I set up all the PCs at the office. The only Dells in the office are those that were purchased before I was hired years ago. All new PCs have been AMD64s on normal motherboards. They like them over the Dells so much, I've built many of them their home-desktops.

Out of your list of things. The only thing worth trying is #2 - in case the included compound has "dried" out - but that is RARE. I was considering it - but its the last Dell PC they purchased. The older ones which have a lot more usage haven't done this. But as I figure, this is perhaps the only shot at fixing it.

Carmichael-07 - thanks for your input. But the noise is a different thing. A noisy/dirty fan is easy. When I am blocking some air-flow from the outside and the fan spins up even faster within a second - its a heat-issue or sensor issue. I'm guessing the normal RPMs is about 2000. But it sounds like its running around 3500+, and when it gets loud - it maybe doing 6000~7000+ rpms. (that is BAD).


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## bernardus (Oct 13, 2004)

I found this site on Major Geeks to Äida 32 download
http://www.majorgeeks.com/download181.html


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## bernardus (Oct 13, 2004)

I can't believe that a sensor will react within a second or so.
Have you tried another fan?
If you close a fan it can run faster because there is no resistance or airmovement.
Vacuümcleaners can do that to.


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## Compiler (Oct 11, 2006)

I have been using AIDA32 for years... and still use it. But its not allowed to be installed on PCs anymore... and the old versions have problems with newer hardware. Dells systems prevent active monitoring of CPU TEMP and RPMs. But I tried that anyways when the problem first appeared. Only the HD temp sensor comes through since it doesn't go through Dell's BIOS/system to register.

I know how fans work, I've built over 500PCs. And I double checked on another Dell of the same type. There is a difference from air-resistance and the motor activily spinning up.

I can cover my whole rear-fan and my fan doesn't change its speed. I can cover half the fan on the defective dell and it gets much faster.


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