If anyone does not feel 100% comfortable doing any of this DO NOT DO IT! I take NO responsibility for what YOU do to YOUR computer, this is a how to, do what you wish with the information. This site is independently owned and operated, the opinions expressed here are not necissarily those of Dell. I have no affiliation whatsoever with Dell. If you like this mod, please feel free to make a donation. There is a link at the bottom of the page. This site is run for free and the information I share is 100% free, however I did take some time to develop the methods described within. Enjoy!
If anyone needs this mod performed on their machine, please email me to discuss.
Small Philips screwdriver
Tiny flathead screwdriver (for removing power button surround)
Some sort of thermal compound, ideally Arctic Silver 3 or 5, but any 99% silver thermal compound should do the job, just make sure its silver!
600 grit sandpaper
OK, the problem is that Dell used some crappy or no heat transfer material between the processor and heat sink. Not to mention, the copper is very poorly lapped and is fairly rough, which is bad for surface area, which is imperative for good heat transfer. Aside from the dust issue, which has been covered already, this is a major problem. This fix essentially makes the dust problem a non-issue. Here is the step by step, the solution.
2) Carefully unplug the power button
3) Remove the 3 screws at the top of the keyboard (here are 2 of the 3, but you get the idea)
4) OK, this is what we have under the keyboard
5) The part in the upper right, with the part # beginning with a 60.42z02Ö..remove that, slide it straight down towards you if you are looking at the computer the way you use it
6) Now we are looking at the top of the heat sink/fan unit. It is held in by 4 screws, remove these screws
7) Now comes the tricky part. The thermal goop they use is a waxy stuff, and when itís cold, it will stick to the processor and heat sink and probably rip it out of its socket. I got the computer good and hot before I did all this so the stuff was nice and melted, on the other 250n I have, it had zero, as in not any, thermal compound on it, and so it came right apart. If you can not easily get them apart, DO NOT TWIST! I can not stress this enough, as it will bend or possibly break pins off the processor. Pull STRAIGHT up on it. Once the heat sink is out of the way, you will be looking at this:
Yours will not be as silver (this has Arctic Silver thermal compound on it), but will look similar.
Here is the heat sink:
The copper part at the top is what we are focusing on (again mine is smeared with silver compound; yours will be bare copper, maybe with waxy stuff on it)
Remove any residual thermal material from the copper with a razor and some Isopropyl alcohol, try not to nick the copper surface with the razor. Now take that 600 grit paper and give the heat sink a good polish. We are not trying to actually remove a lot of material, just getting it nice and smooth to accept the silver compound. Once that is done, clean it off with Isopropyl alcohol, as well as the top of the processor. Apply the Arctic Silver compound in a VERY thin layer as the instructions say, you can just about see through it when its applied correctly. While you have this all apart, find some compressed air and blow out the tiny fins of the heat sink, Iím sure a few dust bunnies have collected in there. Put the heat sink back on and tighten the screws in the sequence stamped on the heat sink, go easy on these, it is a heat sink, not a car wheel. You do not want to bottom the screw against the spring, ĺ way down is good enough, the springs do the rest of the job.
Now all we have left to do is reassemble the thing and enjoy! I am going on 7 weeks without a single shut down on either computer. They used to go down at least 3-10x per day. Right after I did this, I ran Folding @ Home (100% CPU load, tons of heat produced) on it for 36 hours straight and had zero problems. Under normal loads, the fan come on for about 20 seconds every 5-7 minutes, the hard drive temp stays right around 82 degrees F, whereas before, I was looking at 100+ temps inside the computer. Anyways, I hope this helps some of you, I know it has done wonders for both of my 250Ns. Enjoy!
****Extreme cooling extras:****
I beat on my computer, encoding DVDs, ripping MP3s, all kinds of stuff, so demand a bit more cooling, even if this isn't my main computer
This is the inside of the thing, right above the Northbridge heat spreader. For extreme cooling, you can drill these holes the rest of the way through to allow more airflow.
Also, on the underneath side of the kayboard, there is a foil backing. This foil is covering about 85% of the back of the keyboard, preventing air from flowing through the keyboard.
I peeled most of the foil off. This alone accounted for a 6 degree F drop in temp.
All in all, if you do all of this, you should not have a temperature issue anymore. I ran mine with a thermal probe on the processor, and it never got over 122 degrees F, before it would skyrocket to over 145 and shut down at around 148.
I also used some Arctic Silver on the northbridge heat spreader which also goes over the ATI video chipset, not sure if it helped, but Dell again came through with the crappy heat transfer material, so it couldn't hurt I fugured. Please note that they use the foam stuff on these, so the heat spreader will need to be bent to make it sit lower as the arctic silver has virtually zero thickness.