CPU Fan Error MSG persists after replaced

Hewlett-packard / X6000
August 11, 2010 at 04:34:43
Specs: Windows XP
I have asked many people, but none seem to know what to do, and I my self have tried everything.
Firstly I bought the computer as refurbished, it worked perfect then the fans packed up, and I was receiving a Cpu fan error message as follows:

512- Rear Chassis Fan. Not detected.

Bus 8 68GB ModusLNK

0 0 A 0 0

Vendor- Modus LNK
Prod- MXJ3073SC680600T

AND then it said press F1 to boot PC

I replaced said fans, with brand new ones, but this message still appears. I have check they are in correctly, and they are.

Every time I turn my PC on I have to press F1 to boot and it's frustrating. I sit there fingers crossed that maybe it will start to behave and work properly, but it doesn't.

My PC is:
Hewlett-Packard s/n: FRB3320DP6

Microsoft Windows XP Professional
Version 2002 Service Pack 3
Xeon(TM) CPU 2.80GHz
2.79 GHz, 3.37GB of RAM

Nvidia GeForce 6200 GFX Card

Thanks please help.

See More: CPU Fan Error MSG persists after replaced

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August 11, 2010 at 04:54:54
If the rear fan is not connected to a header on the motherboard the BIOS has no way of knowing if the fan is there or not.

Your post is confusing because you speak of two different fans. The CPU fan is mounted atop of the CPU heat sink. That fan must be connected to the header on the motherboard marked CPU fan. Any other case fans should not stop the computer from booting.

If the only issue is with the rear case fan then connect it to a header on the motherboard. Or check in the BIOS (setup) screens to see if you can select to disable that message.

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August 11, 2010 at 06:31:52
As OtH said, the fans MUST be plugged into the correct header. CPU fan goes to CPU_FAN header, case cooling fan goes to CHASSIS_FAN header.

The plug on the fan must also have the proper number of pins (usually 3 or 4) & must be oriented correctly. One of the pins is for the RPM sensor & this it what tells the motherboard that a fan is actually connected (or not). If you have the fan plugged in incorrectly or the fan doesn't have an RPM sensor, the motherboard/BIOS won't "see" it & will display an error at startup.

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August 11, 2010 at 07:08:31
They are all plugged in correctly. I have been through it again this morning and can find nothing wrong with the fan.

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Related Solutions

August 11, 2010 at 07:35:27
"Product: Hewlett-packard / X6000"

An x6000 is a Compaq Presario Notebook computer.

"Product # DH162S"

HP Workstation xw6000 (main support page)

User Guide - Hardware Reference Guide


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August 11, 2010 at 07:37:44
So, the computer will start and run after you go through the F1 screen? If so, as I stated, you may be able to disable the chassis warning in the BIOS (setup) screens.

Did you catch the part jam mentioned about the number of leads on the fan? You may have a fan with only two leads connected to a header that has monitoring.

All motherboard headers may not be monitored either.

The CPU is your processor, not the case. You are getting a chassis fan error message, not a CPU fan message. The computer most likely would not run if the motherboard didn't sense a operational CPU fan.

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August 11, 2010 at 07:46:00
Its an xw6000
i tried to edit that, but it wont let me.

yeah the computer is fine after i press f1
i have gone through the bios and there is nothing in there for me to disable the error message.
yeah i did. all the leads and connectors are correct.

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August 11, 2010 at 07:47:39
How is the header you have the chassis fan connected to labeled? How many pins on the header?

Do you know the RPMs of the chassis fan?

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August 11, 2010 at 07:50:32
there are 3 pins
no i dont know the rpms

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August 11, 2010 at 08:03:01
Does the connector on the fan have 3 leads? Is that header labeled Chassis fan? Download speed fan and see if it can shed any light. Get it below.


One other question I should have asked before. Is the fan in question working?

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August 11, 2010 at 08:04:49
If the fan has three or four wires and is connected to the right fan header, and if it spins slower than the original fan did, if it spins slower than the minimum the bios expects to detect by default, or if you can specify the minimum rpm in the bios for that fan and the fan spins slower than that, you will get a false warning message about the fan.
E.g. higher end power supplies often have a three wire connection for one of the two fans in the PS, and if that fan is variable speed, it spins a lot slower when the PS is cool, and that slow rpm may be below the minimum rpm the bios expects for a power supply fan by default.
If you can specify the minimum rpm in the bios , set it to a little under the rated rpm of the fan.
If you can't do that, you may be able to disable the monitoring of , or the warning about, that fan in the bios settings for any fan except possibly the cpu fan.
If you can't do that either, if the message bothers you, you need a fan that spins at least the rpm the original one did.

A third party program, such as the freeware SpeedFan, that you install in Windows can monitor the rpm of the fans and be set so you get a warning message when the rpm drops too low. You may need to tweak it's default settings when you first install it so that it conforms the to speed of the fans you're using.

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October 11, 2010 at 07:46:32
After many frustrating attempts at finding the problem, I took the fan I thought was the problem out of the system, completely. I turned my Pc on, and the same error message appeared...

'512 rear chassis fan'...etc.

Also, it said '512 front chassis fan not connected'....

This is were I think I see the actual problem.
The fan I thought was the problem, actually is fine.
The power supply fan is the one that is playing up.
So I am going to take it down the computer shop on Thursday, to see what they can do about it, as I am not confident enough to try and fix it myself, in-case I make matters worse.
So for now, I am going to hope, my PC does not over heat and die.
The temp at the moment is 107 degrees, I'm going to keep an eye on it. And try and find a hand held fan to blow through the system until Thursday.


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October 11, 2010 at 08:23:11
From HP.com:

"Screen Message:
512 - Chassis, rear chassis, or front chassis fan not detected

Probable Cause:
Fan is not connected, might have malfunctioned.

Recommended Action:
1. Reseat chassis, rear chassis, or front chassis fan cable.
2. Reseat chassis, rear chassis, or front chassis fan.
3. Replace chassis, rear chassis, or front chassis fan."

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