Alien Autopsy: The Death of an Alienware Powersupply

[Jarod997]

This is the story of my autopsy of my Alienware 7700m laptop powersupply. (Full images found on my Flickr account, jarod997). One day, not too long after turning on my machine, after XP had booted up (darn, I can't blame this one on Vista ) I heard a "poof" and the computer shut off. Heat? No, the room was cool. Did the power strip trip? No, the speakers were still on and in that case it couldn't be a power failure either. Wait... *snif snif* oh, that's not good. I look at the brick, no power LED, unplug it, bring it up to my nose and, yup, *snif* fried electronic smell. Mind you, it wasn't dead fish smell, so it wasn't a cap that blew. (Thank goodness, my 4 1/2 month daughter who was next to me might have lost her breakfast.) So here we go on an autopsy journey to determine if this unit can be repaired. The immediate suspects are moving parts (which there are none), capacitors (no dead fish smell, so again not my first concern). Next is a fuse and power resistors. After which we could look at power regulators. In that order

[Jarod997]

Here we have the brick, Li Shin International, blah blah... the sticker says it all. Oddly enough, on the Li Shin International web page, when I do a model number lookup the search engine says "not found" - nor do they list power supplies as a product they sell. Hmmm.

[Jarod997]

The specifics: 20v (a tad higher than average supplies, ok) 9 amps! Woa, that's a tad much. Caution, 9 amps is more than enought to do SERIOUS INJURY AND/OR DEATH! The average user should not attempt what I'm about to do.

That being said, I am now going to ingore the warning "Risk of electric shock do not open".

[Jarod997]

You forgot the [/url] tag.
You could just use image tags with it, like this

Woot, got it, thnx

[Will]

I've always wanted to take one of those apart.

Don't get killed

[Jarod997]

We begin the operation by locating the footpads and removing them. (Where else to manufacturers hide their screws? Oh ya, stickers. ) At first glance it looks like a hex wrench type bolt. I locate an apporpriately sized hex wrench and begin to remove the first screw. After having a bit of difficulty, I take a close look at the screw head, nope, not a hex, but a mini torx. Luckily my wife has just the screwdriver bit in her toolkit (yea, go wife!). The other three come out without any problems.

[Jarod997]

Upon removal of the cover we find, (aside from a broken screw mount), a large aluminum plate. *grr* well, this doesn't help much. This is probably some persons wise idea of a heat sink. Ok, yes, it does work like a heat sink, the plastic case does get hot, but where does the heat go from there? It would have to go from the aluminum plate, through the air (both into and out of the unit), through the plastic, and then out to freedom outside the unit. (See my notes at the end of the post.) Not the best idea IMHO. Well, off it comes.

[Jarod997]

We continue to expose the wound by removing three screws and set them aside. And off comes... um.. off comes the... *grrr* now what? We take out the flat head screwdriver and begin some careful prying. It appears that there was a good amount of thermal compound and a piece of double sided foam on the main capacitor.

We note here that on the AC side (right) they coil the hot and neutral lines (below the connector) and they also coil the ground (above the connector). We also note the (over?) use of aluminum heat plates, isolation plastic and (for lack of a better term) goo.

[Jarod997]

We now carefully remove the interior brick, being careful not to touch the bottom of the circuit board. Upon further examination of the brick, we do not see any visable fuse, either the traditional kind, compact or otherwise. We do not see any browning or excess carbon either. Hm, ok, what's on the bottom?

[Jarod997]

*Gah* Another plate! This one is soldered in. So, out comes the solder iron and the solder wick (great stuff, when used correctly) and off it comes. Again, a little prying is needed as there are some thermal pads keeping the insulating plastic card off the bottom of the circuit board. Ha ha! Protovision I have you now! (Points if you can name that quote! Ed: No points if you look it up )