If you're looking at this site in general, or this Instructable in particular, chances are you're probably your family's resident "tech guy/gal". No matter that your interest is woodworking, or your degree is in electrical engineering, you're the person who's expected to know the secret of turning it off and then back on. You somehow got roped into being the keeper of the wifi password...I could go on, but you're hip to what I'm laying down. All the free work you get roped into doing, though, does have its upside. You're usually the first person your friends and family call when they get a shiny new computer, because it's expected that you'll take the old one. If you're anything like me, you find that siren song difficult/impossible to resist, and if you're anything like me, you have to do something with those old computers before your slight tendency towards pack-ratism becomes full blown hoarding. The bad news is that recycling can be a serious pain in the neck, with no guarantee that your well intentioned efforts resulted in anything more than kids in third world countries exposing themselves to toxic fumes*.
The good news is that uses for old PCs abound. I've used old computers to learn the basics of Linux, I've built retro gaming machines (Puppy Arcade is a blast, seriously), media servers, and on and on and on. In this Instructable, I'm going to walk you through taking an old PC apart.
Okay, but why?
Fair question. For starters, I'm kind of weird. There's something relaxing about taking things apart. In addition, when I was a kid, my old man had a coffee can full of miscellaneous screws, doo-dads, thingamajigs. Sometimes a ten minute root through the can would save a half hour trip to the hardware store. I do that myself, and given that my background is in electrical engineering, I've expanded on the notion a bit for prototyping purposes. There's more to it, of course, and I'll roll through it as part of the rest of this.
*Not that you shouldn't do the work. E-waste is a serious problem, and if you can't repurpose your stuff, please try to dispose of it as responsibly as possible.
Step 1: What You'll Need
First, a quick word about safety:
Gloves and safety glasses are a good idea here. The potential to slip and stab yourself exists, and many parts are held in by pressure clips, which means that sometimes stuff is just gonna go flying. If you aren't taking the power supply apart, you're not likely to run into high voltage capacitors, but when in doubt, using a resistor to discharge a capacitor is a good idea.
Full disclosure: I'm a member of Amazon's affiliate program.
One Roll of paper towels
Step 2: Getting the Case Open
In general, cases aren't held together with too much. This old HP had one knurled screw at the back. This was also a good time to take off the front panel. This will vary from case to case, some cases just have plates over empty or drive bays, this had kind of an elaborate front piece that impeded removal of the HDD and optical drive, but four pressure clips were all that help it in place.
Step 3: Disconnecting the Wiring
If you've ever built a PC, the details of the wiring matter. Even if no one but you ever opens that case, you want a product that looks neat, is easy to service, and suggests that you care about the finished product. None of that matters here. At the risk of sounding crass, my mantra for this part is "If it feels good, do it". Disconnect everything, work from the outside in. Unplug the stuff that you're uninstalling. Go nuts. The process can be a bit like a puzzle, and while a lot of the connectors are standard, you can sometimes find clips on the cables that have to be dealt with. Patience and a flathead screwdriver will get you through.
Step 4: Taking Things Out
Things like the disk drive(s), optical drives, card readers and so on are housed in bays. The side of the case that is removed is where the screws are affixed, so loosen the screws and slide the components out. If you plan on reusing these components in another computer, I'd recommend putting the screws back into the side of the component and storing them together.
Step 5: Cleaning As You Go
There's a certain ick factor at play here.Chances are the computer you've been given hasn't been open since before it left the factory. Expect dust. Flux brushes, paper towels, cotton swabs and even toothpicks are all handy here. Fans are usually the worst for collecting dust; good thing they're also a complete pain in the butt to clean. Still, no time like the present, you're collecting parts and components, not dust bunnies.
Step 6: A Quick Word About Power Supplies
My current desktop has a 750 W power supply in it so this wimpy 300 W power supply isn't worth keeping for use in another computer build (both from a time and size perspective), not to mention that ATX supplies are relatively inexpensive (here's one I've used on another project for example) so go new for computer builds, and save the old ones for ATX power supplies. ATX desktop power supplies aren't nearly as nice as adjustable benchtop DC power supplies, but I also don't really care if I blow up an ATX supply.
Step 7: So Finally, What Do We Get?
Here's a rough score:
1 ATX power supply (300 W)
1 12 VDC fan (big)
2 sticks of RAM
1 dialup modem card
1 DVD drive
1 240 Gb Hard Disk Drive (3.5")
1 card with various card slots (SD, Micro SD, compact flash)
1 lot of screws, springs, and doodads
The motherboard, modem and card reader board will be harvested for parts (see Geotek's excellent tutorial for more info there), the fan, optical drive, heat sinks and ATX supply will find their way into other projects. I may try to salvage the gold from the RAM sticks. All that's left in the recycle bin is a few pounds of steel and plastic.