Viesor Labs

Several weeks ago I decided to take a laptop from my friends that otherwise would be disposed in trash. Its condition could not be better described than as horrible – missing keys; burnt out DVD drive; broken CPU fan causing the computer shut itself down if you tried to turn it on. In addition to all mentioned above, the laptop was almost entirely soaked in vegetable oil – the attempt of the previous owner to fix the CPU fan problems. Finally, to top it off, the owner was a smoker and that in addition to a substantial amount of vegetable oil caused the laptop smell very close to unbearable.
Being a curious person, I really wanted to find out whether I would be able to revive it.

Here are the steps that I took to make the laptop breath again.

• Thorough cleaning and inspection
• Heat sink and fan repair
• Keyboard repair
• Power Cord Modifications
• Memory upgrade

1. Thorough cleaning and inspection

Unfortunately, I did not photo-document this stage and, therefore, can not display the degree or dirtiness and the actual amount of dust soaked in oil that was found inside. Hopefully, a later taken photograph of the dismounted heat sink can give you an idea.

During the cleaning process I used alcohol and petroleum ether (not sure if it can be easily available for home use but it is a great tool to remove oil). Frankly, there are tons of de-greasers available that can be used.

2. Heat sink and fan repair

First of all dismounting a heat sink in an old laptop can be very tricky. Heat conductive films or pastes can adhere quite well overtime. Thus, be very careful while trying to peel off the heat sink. I would suggest to follow directions from the technical manual that should be available from the manufacturer, in my case Lenovo. For me the problem was an ATI graphics chip that glued itself very well to the heat sink – I am sure if I tried to force the sink off it, it would crack the motherboard. Thus I used a small screw driver, pushed it in the gap between the sink and the stuck chip ( do it ONLY if it has a metallic cover!!!! - if you try to do it on a CPU, that usually have an exposed silicon, you will crash the silicon substrate – you do not want this ) Also, it is important not to use the screwdriver as a lever or you will damage the chip, just try to push it in the gap as parallel to the surface as possible.

In order to take the fan off the sink you must unbend the little aluminum rivet looking tabs. They should be fairly easy to bend. Here is a photograph of my fan (after cleaning ).

I knew that I didn’t have other choice than buying a new fan (eBay was the place: one advice, though, - don’t buy a full heat sink+fan combo, as most of the time they are used and will not last long, try buying a brand new fan). In order to disassemble the fan itself just pull the head of the fan off it should be held only by a magnetic field. Later, you also can, only if you want, take off the fan base that holds everything together just by pushing it out of the aluminum frame.

The same day I bought a new fan I decided that I don’t want to wait for the fan to come to test the laptop. I decided to revive the existing one As the wires were torn off I had to guess which one goes where (just by looking at which one matched where + a bit of logic: red is usually +V and blue is ground) and soldered them back on the fan.

Time to test! By looking at the circuit board traces I was able to confirm that the blue and the red wires were power and the yellow - interrupter (power traces are most likely thicker). Then, I hooked it up to a 5V power supply and guess what? It started spinning Common or ground wire it is always easy to find using a multimeter. Simply test if there is 0Ohm resistance between wires and a chassis.

That was good news. The problem was that due to several broken fins, the fan was vibrating too much. Here is what I did to overcome the problem.

almost axisymmetric isn’t it!?

To assemble everything back I used JB Weld epoxy, fixed the fan base in the aluminum frame like that. Isn’t it pretty Next, everything back on the heat sink and, then, back in the computer.

Moment of truth had come! I plugged the fan back in the motherboard turned the computer on and …. nothing! Fan did not work! For a while I was pretty disappointed as I thought that the motherboard was fried. After some browsing of the Internet and not being able to find anything useful time of trial and error came. Minutes later the inspection of the motherboard led me to this area:

It seemed like the fan power control circuit. Inspecting it further and tracing thick, most likely, power traces I was able to narrow down my search to one, looking somewhat transparent, component located right in-between the two black chips. What helped me was a multimeter – I was turning the computer on and then tracing 5V in that area and I noticed that 5V disappeared right after that component. Apparent guess to me was – a fuse. In order to test my guess I took another fuse for 500mA (did not have a smaller one) and tried it in parallel with this component – if it was a wrong spot I would either burn something else on-board (not likely because of 500mA) or the fuse. Luckily, everything went well and the fan turned on. This is how awkward it looked:

At that moment I started feeling way better :), installed my favorite Fedora (F10 this time) and measured the current that the fan draws during the operation of the laptop (tried to run Google Earth) the maximum I got was on the order of 270mA. Finally, all that I had to buy to wrap up this fix was a SMD 0603 500mA fuse and replace it on the motherboard. I decided to buy 500mA just in case if I mis-measured something and to give some space for all weird spikes in power that might happen.

CONTINUED. AFTER THE NEW FAN ARRIVED
New fan arrived and with it the time to get rid of previously created “masterpiece” fan.

I sealed the gap between the fan and tiny heat sink fins with an adhesive aluminum tape (just like it was in the original assembly), put some foam and heat conductive paste and mounted everything in place.

3. Keyboard repair

Here is how the keyboard looked when I got the laptop

I actually took it all apart key by key, washed all of them in alcohol. (It is easy to find instructions on how to take keys off a keyboard, just search the web.) No pictures this time. As well, I tried to clean the surface underneath the keys. After that I realized that the alcohol went under the semitransparent film with contacts and it took me literally several hours to dry it out with a hair blower. The reason why you know that the alcohol is where it should not be is that when you plug your keyboard in it either does not work at all or some keys appear constantly pressed. Just dry it and everything will be fine – patience is the solution.

What to do with the missing keys?! eBay is the answer again. For $3 per key you can get any of them. That was exactly what I did and now my keyboard looks like this:

4. Power Cord Modifications

Forgot to mention that I got the laptop from Europe and obviously it came with a European plug. I took a spare computer power cord that was laying around and modified the one that came with the laptop.

Obviously, DO NOT do it if you don’t know what you are doing. Simply, buy one.

5. Memory upgrade

This is the last hardware related step that I took to make my “new” laptop more usable. I switched 512MB that the laptop came with to 2×1GB that I bought additionally.

Here is a final result:

Budget for the project

To revive the laptop my expenses totalled at $90, plus, I had lots of fun

PS: After reading various online forums I decided not to deal with the dead DVD drive, as most likely, the laser was dead. I did try cleaning the lens, but saw no improvements what so ever.

Tags: computers, fan, heat sink, IBM