[poppyal]

I have been going through the process of rebuilding a Dell Dimension 8400 and, as some of you already know, it has been a real challenge. I am now to the point where almost everything works except the CPU fan. When I plug in the power supply, the CPU fan starts to run at a very high rate of speed until I hit the power button to boot the system. At that point the CPU fan slows down to normal and everything works great. When I shut down the system the CPU fan starts to run at a very high rate of speed again (as soon as the system powers off). The fan continues to run until I remove the plug from the power supply, and yes, I am sure that it is the CPU fan and not the power supply fan that is giving me the problem.

Does anyone have any suggestions as to what might be the problem? I really need some help here - again.

I brought this situation up in the 'chat' area, but I can not stay with my system long enough to work with anyone that might have any suggestions. By posting here, I can return to this as often as my recent health problems will allow, and hopefully I will not tie up anyone's time when I need to get off of my foot.

Thanks in advance for any advice that is thrown my way. I will check back in a little while.

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poppyal!!!!!!

Welcome back! Glad to see you are feeling a bit better...

Kind of a goofy problem you have there. I'm not really sure where to start, so we'll just look at some things experience has shown to cause goofy problems.

Open Device Manager and expand the "Mice and other pointing devices" category. Right click on your mouse and choose "Properties". Under the "Power Management" tab, is the checkbox next to "Allow this device to bring the computer out of standby" ticked?

Then right click on the desktop and choose "Properties". Under the "Power Scheme" tab, what is selected in the "System Standby" field?

wannabe1

[wannabe1]

poppyal!!!!!!

Welcome back! Glad to see you are feeling a bit better...

Kind of a goofy problem you have there. I'm not really sure where to start, so we'll just look at some things experience has shown to cause goofy problems.

Open Device Manager and expand the "Mice and other pointing devices" category. Right click on your mouse and choose "Properties". Under the "Power Management" tab, is the checkbox next to "Allow this device to bring the computer out of standby" ticked?

Then right click on the desktop and choose "Properties". Under the "Power Scheme" tab, what is selected in the "System Standby" field?

wannabe1

[poppyal]

Thanks wannabe1 for the reply. I can only stay out of bed for 15 to 20 minutes at a time, so I hope that this does not prove to be a real pain for you.

The checkbox is not checked for allowing this device to bring the computer out of standby.

There is nothing selected in the system standby field.

Hope this helps.

[wannabe1]

Those are both ok.

Does your power supply have an on/off switch (rocker) on it? If this turns out to be what I think it is, it will be only the second time I have ever seen this problem...hope I can remember what all I did to fix it.

[poppyal]

No, the power supply does not have a rocker switch - just a slide switch for voltage. Are we thinking power supply? I can remove the one from my personal unit just to check the Dell unit.

[wannabe1]

Nope...not power supply exactly. It's a suspend instruction command in the system BIOS. Part of the fix, as I recall, was to power down and then turn that switch off and back on...than start the machine.

This is where my memory comes into play. On some machines there is a setting in the BIOS Setup that addresses this, but I can't remember where in the BIOS it is. I do remember it has to do with the power settings and includes the word suspend. Poke around in the BIOS and see if you can find that and see what the options are for changing it. Wish I had a Dell here to play with on this...no such luck.

Let me know what you find.

[poppyal]

I could not find anything in the BIOS relating to suspend other than what the machine should do if the power is lost. That option is set to "stay off".

I am welcoming any thoughts/ideas that you may have, but I must put my body on the bed so that my foot is at heart level. I will check back after I rest this stupid thing for a bit. Sorry to have to make you wait, I know that you like to stay with a project until it is finished, but I don't have any choice - I must get my foot up. I'll be back as soon as I can. Thanx, wannabe1.

[wannabe1]

You take all the time you need, poppyal. I'll be here. I need to research this one a bit, anyway.

I'll post you an update as soon as I have one...

[poppyal]

Just a quick thought. Everything in this unit has been replaced except for the CPU fan. Mobo, power supply, memory and video card have all been replaced. I installed the CPU in my personal system and it worked fine. Is it possible that the CPU fan itself is bad? This unit has one of those 'tower' type heat sinks and a separate fans that attaches to the rear of the case. This tower affair is about 6" tall and the fan has a shroud of sorts that covers it. I do not have a replacement for this type of fan, and I don't think that this mobo is configured to use the regular plain ol' CPU cooler.

Also, when I boot this machine, I get a message that a "PCI Device" has been found and that it needs the drivers for this device. I have no idea what theye are talking about. There are no pci devices that I am aware of on this system. The video card is installed in a pci slot, but the drivers are loaded for it and there are no problems with it (unless there is something that I don't know).

Anyway, that is all the info that I can think of to help you resolve this mess. I will check back in the A.M. to see if there are any additions to this topic. I am overdue to get my bod back in bed, so I better take care of that.

Kat's daughter, Ashley, took a pretty good spill but the doctors say that there was no harm done in terms of the pregnancy. Wow!!! I am glad of that. That sweet girl does not need anything complicating her situation.

Gotta go for tonight. I look forward to hearing from you tomorrow if you have any good - or bad - news.

[wannabe1]

Hmmmm

I wonder if the PCI bridge isn't installed. Try updating the chipset drivers. 8400 Drivers.

There's a possibility it's not reading the sensors on the mobo. Another thing to check is that the CPU fan is connected to the correct connector on the mobo. There are case fan connectors there, too. The cpu fan bus should be labeled as such.

[poppyal]

Hi, wannabe1. Sorry it took so long to get back to you. I updated the chipset drivers. It couldn't find the file "usbehci.sys" so I downloaded it and reinstalled. This time the installation took. But, it didn't help. I am still getting the "pci device" at startup and I have no idea what that is. Should I maybe try changing the video card since it is plugged into a pci slot? And I am still getting the original CPU fan high speed whenever the system is plugged in and not turned on. Thanx for your help. I just don't know where to go. The CPU fan has a distinctive plug on it and it will only go to one spot on the mobo labeled "cpu fan".

[poppyal]

Hi! I went ahead and changed the video card back to AGP and I still got the same results in terms of the unit wanting drivers for a pci device. I am going to attack the bios again and see if I have missed something there, although I don't feel that I have. I'll talk at you later. Thanks, again.

[poppyal]

Well, I can't find anything wrong. Is it possible that the power supply that I am using is not compatable? It is a 250 watt unit but it is only for a 20 pin connection on the mobo. I see where a lot of the newer ones have a twenty pin connector and an additional 4 pin connector that makes it usable for either type of mobo connection. The one that I am using does not have the additional 4 pin connector, only the 20 pin plus the four pin that goes to the mobo on a separate connector. Is it possable that I need a p/s that has all of the connectors so that I end up with a 24 pin connector and a separate 4 pin connector? I should be so lucky that this is the problem. I know that I am grasping at straws here, but the fellow that is buying this machine wanted it this past weekend, so I am running out of time, money and ideas. Please help me all that you can.
Thanks to all of you.

[wannabe1]

Holy cow, poppyal. I have googled this issue until my fingers hurt. I found a few instances of folks who have encountered this problem, but nowhere did I find a solution.

I guess the best we can do at the moment is to see if we can find the problem the old fashioned way...trial and error.

The first thing I'd try is a different CPU fan as it is the end point of the problem. If a different fan exhibits the same problem, try switching the power supply (the other end of the chain) and see if the problem persists. I am personally leaning towards a sensor on the mobo, but we'll check the chain a link at a time and see if we can pinpoint it.

The power connectors on the mobo should not make a difference so long as they are connected.

[poppyal]

Unfortunately, I do not have a replacement CPU fan that will fit this unit. Any socket 775 boards that I have seen use a fan that is different that the fan on this board. The manner in which the fan attaches to the board is different than the 'normal' type setup. I can, and will, start at the other end and take the p/s out of my system and install it in the dell and see what happens. I will let you know as soon as I can make this happen.
I sure do appreciate your assistance with this dumb situation. I just found out yesterday afternoon that my foot and leg must be amputated from a point about midway between my knee and ankle. Needless to say, I am going nuts trying to tie up a few loose ends such as this before the first of the week. They will be notifying me yet today as to the actual dte and time of the surgery.
Again, thanks for your help. I will get back to you real soon in terms of the power supply helping or not.