Dell Latitude D800 Secondary Fan Repair

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My Dell Latitude D800 had a noisy fan. I could hear the distinctively roughy and gritty noise from time to time as this fan would start up. However, it didn't seem to be coming from the main CPU cooling fan that is located near the left display hinge (as you would see it with the machine open and in normal operating position).

Since its warranty was due to run out in March of 2008, and there were a few other problems that needed to be taken care of, I called Dell technical support and explained all the problems. They were very polite and professional to speak with. The first technician I spoke to assured me that all my problems would be fixed and that they'd send a box out to collect the machine.

They did send a box out. They did not, however, fix all the problems that my computer had. The main CPU fan had been replaced but it did not help. The gritty fan noise would still come and go. It also came back with one new problem--when this machine started up, it claimed to be a Precision M60 instead of a Latitude D800. Oops.

I called Dell again. They were still very polite, but this time I followed the advice given on the alt.sys.pc-clone.dell newsgroup. I enclosed a detailed note explaining the problems the machine was having, including the noisy fan. I was careful to note that I did not think the CPU fan was at fault.

Dell cured all of my computer's ills except one. Yes, you guessed it. They did not get the secondary fan.

Why? I don't know. I probably never will know. Having perused the online service literature for my computer, however, I have come to the conclusion that perhaps the nice people at Solectron (Dell's contract repair outfit, now better known as Flextronics) do not know that there is a secondary fan in the system. The online service literature never talks about such a fan, but it does show up in exactly one illustration:


Ahh...so there it is, to the left of the second shaded arrow. (The above excerpt actually comes from the palmrest removal procedure.)

I wasn't even going to bother sending the computer in to Dell again. If they hadn't fixed it two times now, why would they fix it if I were to complain? (A better question, perhaps, is what might they break or do incorrectly? I know that sounds bad, but I couldn't help but wonder and worry!)

In other words, it was...

Time To Break Out The Screwdrivers!

I know there's a second fan in the system. Some exploration with the excellent i8kfanGUI software proved it long before I ever saw the above illustration. And while I generally dislike servicing laptops, I have done it before. This time I even had the benefit of service literature, whereas before I did not.

Then I got to thinking--I'm not the only Latitude D800 owner out there who might have this problem. So I made this page to describe the process of removing and repairing the secondary fan in my computer.

It should go without saying that if you are doing any of this to your own Latitude D800 laptop computer, you are doing so strictly at YOUR OWN RISK! If you break your laptop, damage something, hurt yourself, hurt others or anything bad happens, YOU are completely responsible for the results. This information is presented as a good faith effort, but I make no guarantees that it is accurate or safe for your laptop. All I can say is "it worked for me". Your mileage may vary.

Also: A GOOD set of precision hand tools is a REQUIREMENT. Do NOT even THINK of doing this with poor quality or inappropriate tools. If you don't have good quality precision hand tools, go out and buy some right now. I'll wait.

Got your precision hand tools now? Good. You're almost ready to use them.

You will also need:

• A clean space to work.
• Plenty of light.
• An egg carton to hold screws
• A pen or marker to label the compartments where you store the screws
• Some kind of oil. Motor oil or light machine oil is suitable for this task.

What Does The Second Fan Do?

After taking my system apart, I can tell you exactly what it is used for. Not only does it help to cool the graphics processor, it also serves to cool the chipset--or more accurately, it helps to cool the Intel 855 north bridge portion of the chipset. I didn't even see the south bridge while inside, so it may be on the underside of the board or underneath another part. In any case, most south bridge chips don't get all that hot in normal operation.

Getting Started (or "where is that fan?")

Shut your computer completely down. Do NOT put it in standby or hibernation. Disconnect the AC power adapter and remove the battery. Work in a well it area. Print these instructions out for reference or have a working computer nearby while you do this.

If you looked at the illustration above, the second fan is under the keyboard. I'd place it beteen the U and P keys, or maybe a little higher than that.

To get to the fan, you will need to start by removing the topmost trim piece--the one that has the power button and your computer's model number printed on it. This is designed to pry up from the left hand corner. Insert a fine-tipped bladed screwdriver into the "pry point" that is molded into the module.



Tilt the display all the way back. It will go nearly flat. You have to do this before removing the trim, or it will not come up.



CAREFULLY pry the trim loose. It is held in a few different places. When you get all the way to the other end, there is a cable that provides power to the status LEDs. This is a "tape" style cable. Using the grip provided on the connector (do NOT pull the cable itself) disconnect this. At this point you can set the trim panel aside. You are done with it for now.

What you have now should look a little like this:


In the picture above, I have pointed two screwdrivers at the keyboard screws. You will need to remove these. Although one screwdriver in the picture is a bladed type, both screws are phillips head screws. Remove them and set them aside.

Note: Some of the screws you will be removing are of different types. Length, fineness of the threads and thickness will differ. It would be a good idea to get something like an egg carton to put the screws in. This will not only keep them from rolling away...you can also label the compartments so you know which screws went where.

The keyboard should be a little loose at this point, but chances are it will remain firmly in place. This is because there are two "tips" on the upper right and left sides of the keyboard assembly. They need a little persuasion to come loose.



When you get them both freed up, the keyboard will lift out. This is a delicate assembly--don't force it. (You shouldn't force anything during this procedure, but this is doubly true for the keyboard.) At this point the keyboard will be "free". It is still plugged in to a connector on the motherboard. You can unplug it if you want. It is possible to do everything you need to do with the keyboard plugged in, but it does put some strain on the cables going to the "trackpoint" device in the middle of the keyboard. If you want to unplug the keyboard, move it so you can see the blue grip tag on the connector. Grasp this and pull it straight up.



Set the keyboard aside. Put it somewhere where it won't fall on the floor.

Now you can see the fan in question quite clearly.



You can see that Dell has used a so-called heat pipe to channel heat away from the graphics processor and north bridge. It leads to a little radiator like structure that the fan blows through.

This is why many laptops get overheating problems later in their lives. These little radiators plug up over time and become lots less effective at removing heat. As a result, the computer overheats and eventually breaks.

To get the fan out, you will be removing some metal shielding, the video card, LCD connection cable and more than a few screws:



Start by removing all four screws from the thick heatsink plate (this is the piece that says "Auras" in the picture. There is a fifth screw that should have been in the picture but wasn't because I had done this once before and forgot to put it back in place.

Now unscrew the other screws, labeled as "more screws" above. These screws secure a thin metal plate. When all is said and done, you should be able to remove the thick "Auras" plate as well as the thin metal plate. Keep in mind that the thin metal plate has tabs that hold it to the video card near the two bottom screws. As such, you will have to play around with it a little bit before it will come out. It bends easily, so be careful.

Make sure you separate the screws by type and label where they go. Dell does provide a nice printed guide (which you can see at the lower left of the picture) for some of these, but it is no replacement for keeping everything labeled so you know exactly how it goes back together!

You should have a heatsink all by itself, with an attached radiator when you get done.



That's right. The fan doesn't come out with the heatsink. It is attached to a thin metal plate that runs underneath the video card.The metal plate is anchored by four holes drilled through the video card's circuit board. Its purpose is to make contact with the chipset to let it shed heat.

Before going any further, you might want to clean the lint out of the radiator. Since you're in there anyway, why not?



The video card is now visible.



What it is NOT, however, is free. Do not try to remove it just yet. Carefully pull up on the edges (and NOT the cable) leading to the display panel connector. This is the silver connector at the top of the picture above. Disconnect it and lay it aside. You will find a screw underneath it. Remove this screw and put it away.



The video card is connected via a large plastic plug at the lower left corner. Ease the card up, focusing on this area so as to avoid putting undue strain on the connector. The fan assembly will be loose, but it should come out with the card.

When you get them out, you can see the north bridge:



On the video card side of things, you'll have something that looks like this:



If your fan is like mine, it may have come out of the four holes that hold it to the video card.

There is thermal compound on the bottom of the metal plate that the fan is attached to. This compound is pressed against the face of the north bridge when everything is put together. If you're careful and don't disturb it too much, you won't have to try to re-apply it. I found the compound on this assembly to be pretty rigid.

 And here is the fan by itself:



Now it's time to remove the fan. There is an easy way and a hard way to do this. The easy way is to remove the lone remaining black screw from the fan assembly. When you do, it will lift right off the metal base plate with only a little encouragement. Once you get it off, you will be able to see the back bearing. This is what we want to pay attention to. Carefully (and I do mean carefully) disconnect the wiring from the video card.

At this point, you'll either think I'm completely nuts or resourceful. Whatever the case may be, the fan you have now isn't something that you can just run out and pick up from your local electronic parts retailer. Even if you could, it would probably go bad in about the same length of time. Whether you agree with me or not, what I'm about to show you has worked very well for me over many years and countless fans. I haven't had a one come back with noisy bearings after doing this.

Turn the fan over so you can see the manufacturer and information label. Hold the fan in place. Using your other hand, take your bladed screwdriver and start to peel the fan label up.



With any kind of luck, you will see the fan bearing soon.



Get some motor oil and a cotton swab. Gently moisten the bearing. Work the fan a bit by either twirling the blades gently (!!) with your finger or blowing on them. Clean up any excess and put the label back on as best you can. If it won't go back on, make sure you've cleaned up all the oil residue that didn't go in the bearing. Failing that, make a new "label" with adhesive tape. Whatever you do, don't just leave it off. That could be inviting a disaster.

Screw the fan back to the metal plate.

Mate the video card and fan assembly once again. It will look like this if you got it right:



Plug the video card into its connector at the lower left. It should "click" into place. Do NOT force it. If it doesn't want to go in, check the alignment and try again. It may take a few tries. Make sure you plug in the fan power connector!

Fasten the screw by the display panel connector. You can connect the display panel now if you want to.

Now you will put the heatsink and shielding metal back in place. The thin metal has a kind of "tab" that you will need to "hook" in under the lower edge of the video card. It takes some fiddling but can be done. It may help to bend it outwards gently, seat it and then use your bladed screwdriver to push it back against the circuit board.

Fasten the rest of the screws in place, all the while making sure that everything is aligned properly.



Plug the keyboard back in. Set it back into place.



The keyboard needs to be put in starting from the spacebar and working your way up to the tips on each side. It should lay relatively flat when you have it in place. Replace the two screws that hold it into place.

Find the trim panel and plug it back in to the connector near the right hand display hinge. Seat the right hand corner and continue to work your way left. You will have to push it down a little to get it back into place.



Make sure you are not pinching anything as you seat the trim panel. Push down firmly on the panel to make sure it is back in place. Reconnect power and reinsert the battery. Lift the display panel up to a normal viewing angle.

Turn on the computer. It should start up right away. If it doesn't, turn it off, disconnect all power and go over the steps presented here carefully. You may have forgotten to plug in a connector or something.



Using a utility such as i8kfanGUI, check to be sure that your fans turn on and run*. Also pay attention to the temperature readings.



That's it. Now your Latitude D800's secondary fan will run smoothly and quietly for many years to come.

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Copyright ©2008 William R. Walsh. All Rights Reserved. Permission is granted to reproduce this material in whole as long as no fee is assessed for access to this information outside of costs required to cover connection time or duplicating expenses. This content is not to be displayed alongside advertising materials of any type. This information and procedure are provided in a good faith effort to help owners of Dell Latitude D800 notebook computers repair a noisy secondary fan if their computer has this problem. It is not intended to solve any other problem or issue. Any damage to your computer caused by following this procedure is your responsibility. Do this only at your own risk.

* If you do not want to use i8kfanGUI, the Dell Diagnostics utility (press F12 at startup on most machines) will test the fans. I don't know if it tests both fans or not. I do know that it starts the primary (CPU) fan when it is supposedly testing the video card fan.

If you reproduce this material in any way, you must provide a link or reference to the original work. You may use portions of this work in other projects provided that you link back (or supply a reference) to this page. Such projects may not be illegal, dangerous, rude to others or displayed with advertising materials of any type.

This page is not affiliated with Dell Computer Corporation in any way. No one at Dell Computer Corporation has approved or endorsed this advice.

The palmrest removal illustration featured at the top of this page is Copyright © Dell Computer Corporation. It is used solely to display the location of the fan. It is extracted from the Dell Latitude D800 service manual.