8-25-2006: I had a disk crash and am still trying to put the pieces back together. I pulled the text from Google's cache, hopefully I have the images (and the rest of the site!) on a backup somewhere.
Disassembling a Dell Latitude CPx J650GT notebook
I bought this laptop used sometime late in 2003, at which point it was about 3 years old. It worked without issue for awhile, until the bearing in the cooling fan wore out near the end of December. Whenever it ran, it would make a loud rattling sound, and under heavy load (I run distributed computing projects for TeAm Anandtech on it 24/7) the CPU would get dangerously hot, as high as 60° C if /proc/acpi/thermal_zone/THM/temperature is to be believed. A replacement was needed, so I decided to take the laptop apart piece by piece to see what sort of fan I had to deal with.

Step 1: Prepare for battle

Before I could start tearing apart this beast, I first needed to clear off some space and gather my tools. The tools you will need during this adventure are:

  • A small but long-shafted philips screwdriver: Too short and you don't get enough leverage, too big and it won't fit.
  • A flathead screwdriver or some other prying implement
  • Something to keep the screws in
  • Dell's service manual

With my workspace ready and my tools in reach, I got to work:

1. Shut down the laptop and unplug it.
2. Remove the battery, modular bay device and PC cards.
3. Remove the hard drive screw.
4. Pull down on the hard drive cover to create a "handle", then pull out the hard drive.
5. Turn the laptop upside down.

Upside down with all peripherals removed

Step 2: Remove the keyboard

Now we're getting serious. :)

6. Take out the screws labeled "K" on the bottom of the laptop.
7. Turn it right side up and open the screen.
8. Stick your prying implement under the "blank key" on the right side of the keyboard and lift it up.

Lifting out the keyboard

9. Lay the keyboard over the left side of the laptop, upside down.
10. Unplug the keyboard cable (2) by pulling straight up on it, then remove the trackpoint cable by pushing out the black clip of the ZIF socket (1) and then pulling out the cable.

Exposing keyboard wires

11. Put the keyboard aside.

You now have most of the motherboard exposed. This should be enough for most internal maintainence, but in this case I need to go even further. Below is an annotated look at the exposed inside of the laptop. The cable labeled "X" is the display cable, and the one labeled "Y" is the palmrest cable. Keep these in mind, I will refer to them later.

Annotated look at the motherboard

Step 3: Remove the display

I need to remove the motherboard, and to do that I need to remove the palmrest, and to do that I need to remove the screen.

12. Unplug the display cable by pulling up on it.
13. Close the screen.
14. Turn the laptop around so that you're looking at the back.
15. Remove the "D" screws.
16. Open the screen.
17. Remove the screen. It just snaps off, but be careful not to break the plastic. It can be a little tricky.

Now the display has been removed, and the laptop feels MUCH lighter, and also a lot more flimsy. You're looking at something like this:

Rear view of the laptop without the screen

Step 4: Remove the palmrest

It is now time to clear the final obstacle that stands between you and the motherboard: the palmrest.

18. Unplug the palmrest cable by pulling up on it.
19. Turn the laptop upside down.
20. Remove the "P" screws.
21. Turn it right side up.
22. Remove the palmrest. Again, it just snaps off, and again you must be careful not to break it.

With that gone, you now have a circuit board in a plastic tray:

Top view of the laptop without the palmrest

Step 5: Remove the motherboard

For what I have to do, this normally unneccessary step is neccessary.

19. Loosen the screws under the PC card slot and to the right of the CPU assembly.
20. Tilt the front edge of the board up and pull it out towards you.

We've seen about enough of the top of the motherboard, so here's the seldom-seen back of it:

Back of the motherboard

21. At this point you might want to remove the RAM, to eliminate any possibility of it being damaged.

By now I had easy access to the fan, which I could see now was a 30x5mm Sunon GM0503PEB1-8. I guess maglev bearing technology isn't very good, considering the thing only lasted 3 years. To remove it, I need to remove the heatsink assembly.

Step 6: Remove the CPU RF shield

Not only is the heatpipe contact plate underneath the RF shield, but the shield itself blocks the heatsink screws.

22. Loosen the 3 recessed screws at the inside corners of the shield, and the 2 screws at the corners of the heatpipe contact plate.
23. If present in your laptop (it is in mine), remove the black screw to the lower left of the shield.
24. Remove the RF shield.

Step 7: Remove the heatsink assembly

The final step of the process is to remove the heatsink assembly. In the picture below you can see the heatsink itself (1), the heatpipe contact plate (2), and the screws from hell that must be removed (3).

CPU RF shield

25. Unplug the fan cable.
26. Remove the heatsink screws.
27. Remove the heatsink assembly.

That's it. The laptop has been completely dismantled piece by piece. Good luck putting it back together.


As a bit of an epilogue, I was unable to find a suitable replacment fan, so I bought a whole new heatsink assembly on eBay. It cost me $18, but I doubt I could find a cheaper solution.

And as a bonus for reading so far, here's a "blooper reel" of everything I did wrong the first time around:

  • Scratched, bent and nearly broke the screen assembly
  • Ditto with the palmrest
  • Reamed out the head of one of the RF shield screws, broke off the shield, only later managed to get the screw out
  • Removed the fan by cutting the cable

Electroblog.com
2006-08-16 8:31 AM EDT

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