Dell SmartStep 250N Overheat Solution

I have an old Dell SmartStep 250N and let me tell you it's been hell trying to figure out a solution to the overheating problem.

Symptoms:
Computer runs for a period of time, but as soon as the CPU usage spikes and the CPU fan kicks in the computer automatically shuts down.  Things like playing mp3's and video files for a sustained amount of time causes the shutdowns.




Solution:
My 1st try at trying to fix the problem involved replacing the heat distribution material on the CPU.  That helped a little, but didn't get rid of the overheat shutdown.  Here's a link to a post showing replacement of only the heat distribution compound.

My 2nd try has been very successful. I used Matt Koestner's Dell SmartStep 200/250N Overheating Problem Solution.  I can play video files and mp3s continuously and use the computer much more aggressively than before.

The solution addresses 2 issues:

1. Improve heat distribution from the CPU to the heatsink
2. Improve airflow

Improve heat distribution from the CPU to the heatsink:
The CPU heatsink that is installed in the Dell SmartStep 250N is not designed well and if you look at it carefully, the surface is not smooth, but lumpy. This reduces the contact between the processor and the heatsink thus resulting in poor heat removal from the CPU.

To improve the contact between the processor and heatsink, the finest sandpaper you can find (I used an 800 sandpaper) and smooth out the bottom of the heatsink. The sandpaper basically feels like gritty leather. The idea is not to grind the surface of the heatsink but to polish it down so that it's smooth and free from lumps that would reduce overall contact to the CPU.

Once you polish down the surface of the heatsink, apply a thin layer of heat distribution compound to the heatsink.

Also apply a thin layer of heat distribution compound to the top of the processor.

Improve airflow:
Finally, cut way the foil on the underside of the left hand side of the keyboard.  Keep the thin foil strip at the top of keyboard because that keeps the plastic anchors from melting off from the heat.  Be sure to cut around the keyboard part number labeling so that you know what keyboard part number is in case you'd like to find a replacement.  You'll notice a significant amount of air flowing through the keyboard once you reassemble the computer.

Matt Koestner goes much further with the cooling, but I find that removing the foil from the bottom of the keyboard is sufficient, but I do like the idea of improving airflow from the bottom of the computer.  You'll notice there are small holes on the Dell SmartStep 250N.  It wouldn't hurt to help out and add more.

2011-08-11 Update

I was using the Dell SmartStep 250N without a cooling pad and noticed some odd behavior, most notably, intermitten reboots after Windows logoff/logon.  I monitored the CPU temperature and it's stable, but when I flipped it over to check the memory bay, the memory chips were HOT.  I put a notebook cooling pad underneath it and the reboots went away.  I'm thinking maybe I should try adding thermal pads to the memory door to pull the heat off the memory chips:
http://shop.ebay.com/i.html?_from=R40&_trksid=m570.l1313&_nkw=thermal+pad&_sacat=See-All-Categories

For now, the notebook cooling pad is doing it's job.

2014-02-13 Update

I've decided to revisit this cooing mod since it's been a while since I've started and I have to say, this computer started it all. I was still having problems with this computer shutting down on me randomly even while it was sitting on a cooling pad. I never looked into anything else except the CPU on the Dell SmartStep 250N.

Before getting started, another observation. For a desktop processor, the heatpipe is WAY TOO short. My experience with the HP Pavilion tx1000 and Dell XPS 15 L521x shows that short heatpipes are never a good idea. The heatsink is simply poorly designed for a desktop processor.

I reopened the SmartStep 250N and found that the thermal paste was still in good condition. However, the GPU and other chips are not visible. They're hidden underneath the metal plate to the left of the processor.

Removing the metal plate shows the ATI Mobility Radeon M6 and an Intel chipset chip (I believe).

The metal plate acted as the heatsink for both of these chips so I removed the thermal pads and replaced it with Artic Silver 5 and a copper shim.

In next photo, I had put put the metal plate over the chips and pulled it off to take a picture and the copper shim over the chipset chip transferred over to the metal plate (heatsink). I did NOT add 2 copper shims to the chipset chip.

I reused the thermal pads since they were in good condition and added another copper shim on top of the metal plate (heatsink) to help pull the heat of the metal plate.

Additionally, I added a thermal pad and a copper shim to the top of the heatsink to help pull heat off the heatsink and fan assembly. For this computer EVERYTHING and I mean EVERYTHING helps. Remember, the Dell SmartStep 250N has a desktop processor in it.

Before the additional cooling mods, the Dell SmartStep 250N idled at about 60 C. Now the system idles at 55 C. Personally, I think the biggest help was properly cooling the chipset chip. These chips are never properly cooled and in my experience, do cause problems.