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Fixing the Dell SmartPC/SmartStep 250N overheat

Or how to fix a conception default.

By sébastien Closs, 26 oct 2004. Updated the 08 may 2004.

WARNING : This tutorial is made to help you in your research, and to give you a preview of the work that has to be done to fix this problem. I recommend you to be very careful during your operations, and if you feel not comfortable with it, don't do it ! I can't be responsible for any operations done in a wrong way, which may conduct to a data loss or a component destruction. Operations described here shoud be done only if all others possibilities failed (please contac your manufacturer first).

• the problem
• How to fix
  1. What you need
  2. Opening the laptop
  3. Preparing the heatsink
  4. Adding new thermal paste
  5. closing
• Conclusion

I - The problem

On this serie of laptop, Dell neglicted the thermal dissipation. These laptops, for performance and cost reasons, use a Intel Pentium 4 processor, in the version made for desktop computers, and are not a specific version for laptops (Pentium 4 Mobile theorically). So, it would be nice if this desktop version of the Pentium 4 was not a so big electricity eater nor a so big heat producer.

This is the problem. Mobile Pentium 4 are made to minimize the consumtion and heat production : this is a reason why this processor is twice to 3 times more expensive than the desktop version. Dell, and other manufacturer putted the desktop version (cheaper and more powerful) in the laptops, but they kept the same dissipation system than ordinary laptops (so a dissipation system originally adapted for the Pentium 4 mobile).

Result ? The fan is always running at the highest speed, so it's very noisy. And, if you use your computer intensively (video compression, seti@home), the computer may shutdown without any warnings. It's the security system which turn it off to prevent the processor from burning. When it's very hot in the room, the computer can shutdown after only 5 minutes, and many times per day.

This problem is common with laptops from Dell, Acer, Gericom and Fujitsu because they share the same base and box. All these manufacturers use the same provider.

II - How to fix

Unless you want to change your processor, there is no real good solution. But the fix I propose has already been done very successfully on many computers from Dell, Gericom, and Acer.

First, the thermal dissipation system is not adapted to the processor, but very often, it's mounted in a very bad way. In fact, to evacuate the heat efficiently, we need very good components.
In all computers, the processor should evacuate the heat it produces to a heatspreader (aluminium or copper block which transmit to the ambient air the heat it receive from the processor). With the processor we have actually, the heat became a crucial problem. To optimize the heat evacuation, the contact between the processor and the heatspreader must be perfect. To improve this contact, we can use some thermal paste (in silicon, or better, with some metal-iron-copper particules) to fill the microscopic holes (asperity) of the surface of the processor and more, of the heatspreader.

Here we can begin. Our work is to open the computer to reach the heatspreader and processor, then to clean all these parts, to verify the surface, to put the thermal paste, and finally to assembly all back.

1 - What you need

• A little screwdriver (crossed)
• A little screwdriver (flat)
• Thermal paste with copper or iron particules (Artic Silver 3 or 5 are the best-sold at every computer resseller).
• Be careful about the static electricty. (Touch a big metal mass or earth connection to discharge you)
• Your computer has been runing on for 30 minutes to 1 hour before (the actual thermal paste will be easier to remove)
• Plastic gloves, or plastic bag.
• Cleaning product: alcohol or other.
• Cutter

2 - Openning

- Disconnect your computer from the electrictal socket.

- Put your screen entirely flat (horizontal).

- With the flat screwdriver, remove the part 1 (the one with the On/Off button) as on the Figure 01. Be careful to remember  the connection of this button. Disconnect it.

Figure 01 : Openning.

- We can acces to the keyboard. Find the screws (Figure 02), and remove the keyboard. (Figure 03).

Figure 02 and Figure 03 : removing the keyboard.

- Remove the metal part as on the Figure 04.

Figure 05 : removing this metal part

- Remove the 4 screws of the dissipation system (heatspreader + fan - Figure 06).

Figure 06 : removing the heatspreader

3 - Removing and preparation of the processor

If your computer was working a while, the original thermal paste should be soft enough to be easy to remove.

- Remove the heatspreader slowly. Be very careful and slow if the processor come with it.

- Open the system (Figure 02), and remove the processor from its socket (Figure 07).

Figure 07 and 08 : removing the processor

- In my case, there was one aluminium foil between the processor and the heatspreader. This foil was isolating the processor from the thermal paste, and the thermal paste from the heatspreader. That's not good. I removed it with a cutter. Sometimes there is no foil, and no thermal paste at all.

Figure 09 and 10 : Aluminium foil to remove

- Clean the heatspreader and the processor (Figure 11 and 12). The surface should be perfect.

Figure 11 and 12 : the result of the cleanning

4 - Putting the new thermal paste

- A very thin layer of thermal paste is sufficient. (less than 1/2 mm). Put one little quantity on the heatspreader, then you can arrange it with your finger (with gloves). The gloves avoid the asperity of your finger skin, so the layer of paste will be very thin and very flat. The thickness should be homogene everywhere. Very very thin, and clean it a little so the metal is visible. The paste should only fill the little asperities of the metal. (Figure 13).

- Do the same on all the surface of the processor. (with a thermal paste layer very very thin too). Figure 14.

Figure 13 and 14 : Putting the thermal paste

5 - Assembly

- Assemble all removed parts in the order :

1. the processor (socket system)
2. heatspreader (screws)
3. the little metal part (screws)
4. the keyboard (screws)
5. the top with the On/Off button to connect (clips)

Figure 15 and 16 : Assembly all the parts back

III - Conclusion

Your computer should be much more quiet, with a fan working less often and at a lower speed. The shutdowns are ended.
Some people went farer, and continued to remove parts, until they arived to the chipset and the graphical card to change the thermal paste there too. I didn't go so far, and I'm very satisfied of my result.