5 Tips For Disassembling
A Computer System
Disassembling a computer can be a painful task. If you're planning to slot in a new hardware component or want to look inside your PC, disassembly cannot be avoided.
Although disassembling a computer can appear to be a daunting task for beginners, it is really not that difficult.
Well fret not. This article covers are some important tips which you should remember. These include things like cutting off the power supply, opening the case slowly and disconnecting various components.
1. Cut Off The Power
Now pay attention. This is important. The first thing to do when disassembling a PC is to disconnect your computer from all power sources. Rip out that power cord - I've had too many occasions when my PC was still connected to the wall outlet and I accidentally stated disassembly - with disastrous results. So always remember to do this step first.
2. Open the Case Slowly
Next, you want to open the computer case slowly. Some PCs slide off the side - and you may need to remove some screws before the cover can come off. Others open in different ways. You need to check your specific computer case.
Some cases (e.g. those from Antec) are in fact better designed and allow you to open the case easily. I always like to go for such computer cases - you can check them out at this link.
3. Learn What is Inside the Case
Once that computer case comes off, you need to familiarize yourself with the internals of your PC. If you want, you can take photos. Usually, the things to look out for are you video card, hard drives, sound card, CPU, memory modules.
4. Disconnecting Adapter Cards
If you need to remove adapter cards, e.g. a PCI based sound card, you will need to take note of the screw at the top of the bracket. Remove that screw first, then you'll be ready to disconnect the card.
5. Disconnecting Disk Drives
The other point to note is regarding disk drives. Disk drives (hard disks and floppy disks) usually have screws at the side to secure them in the PC's drive bays. Make sure you unscrew those carefully and hang on to the drive while doing it. You certainly don't want you precious hard disk dropping on the motherboard.
You now know some tips for disassembling a PC. Its important to bear the above points in mind when opening up your PC - it will save you a lot of headache and avoiding any potential problems. Good luck and happy computing!
Disassembling the Computer
It's Not a Race
If you are familiar with the procedure of disassembling a computer, then you can skip this section. If you are a beginner and actually want to learn something, then document well, and learn or re-affirm your knowledge about everything you see inside. Given a screwdriver, a 10-year old could probably have the computer apart in a half-hour or so. If you're using this section as a lab or learning assignment, and you have your computer apart in the same time as a 10-year old, then that's the level you'll be at. But if you take a slow relaxed approach, discuss, question and research each component as it's removed, you'll learn alot. Read the sections on What's Inside and What You See, fall back on your own knowledge, use the Internet, your books and resource material. It's impossible to retain all the information, so one of the most important computer skills you can learn is how to research and use your resources to find what you need. Here's an example of some questions to think about or discuss as you proceed:
- Should I document everything I do or everything I remove?
- Am I taking the best ESD precautions available to me right now.
- When you remove an expansion card what kind of card is it? What kind of expansion slot did it come from? How many bits wide is that slot? What is the bus speed? What does the card do? If there's any wires attached to the card, what's the other end attached to and what are the wires or cables for. What kind of port is on the end of the card?
- When removing a drive, what kind of drive is it? Is there information documented right on the drive itself? What kind of power connector does it use? Are there jumper settings on the drive? What for? Are any drives connected together or do they all have their own cable? Does it matter which cable I hook up when I reassemble? What are some of the things I know about this particular type of drive?
- When removing wires or cables, what are the cables for? Which connectors are actually being used and what could the other ones be for? Are they following the pin-1 rule? Is pin-1 actually designated on the device the cable is attached to? Is it designated in more than one way?
- Am I still taking proper ESD precautions and is my antistatic strap still hooked up?
- Look at the motherboard again when there's not so much in the way. Can you point out the CPU? How about the BIOS chip, the battery, cache RAM, keyboard connector? Is it an AT, Baby AT, or ATX format? Is there a math coprocessor? Where is it? Is the system memory supplied on SIMMs or DIMMs? How many pins on the memory module? How many memory slots are thee for each bank of system memory? Is the CPU installed in a ZIF socket or a friction socket? Are there any jumpers on the motherboard? Is there any information silk-screened on the board itself?
This is just an example of the questions you should be asking yourself. Try to come up with lots more. Even if you are not prepared to actually take your computer apart at this time, just take the cover off and ask yourself these questions as you visualize the various steps involved. Remember, not all questions can be answered by a single resource. Look in your notes, check out your manuals and resource material, ask questions.
Read the section on Electrostatic Discharge and always take ESD precautions. Remember, if you can feel a static shock its probably close to 3000 volts. Some ICs can be affected by as little as 30 volts.
- Always use an antistatic wrist strap.
- Keep a supply of antistatic bags to place components in as they are removed.
- Leaving the computer plugged in is a recommended procedure. However, make sure it's switched off and remember that the cable going to the remote switch on the front of the case carries AC current at house voltage. Also, ATX motherboards have power to them all the time, even when the switch is off. Before beginning to remove a power supply or an ATX motherboard, always make sure your computer is unplugged.
You want to make sure you have what you need. Your wrist strap is attached to the computer, you don't want to have to run to the other side of the room or to another room to get something. Forget about the strap and your computer may follow you.
- Have a pen and paper ready. Documentation is real important. After you've changed a few jumpers or removed or replaced a few cables and cards, you probably will have to put some back the way they were. If you have documentation, putting things back together can be a simple reverse process. This is true of software troubleshooting as well.
- Make sure you have the tools you need and they're all close by and handy.
- Be sure to have a container to keep the screws in so you have them when you want to put things back together.
- Make sure you have the resource material, drivers or software that you may need.
- If possible, enter the CMOS setup and record the information available. At least record the floppy and hard drive configuration and any settings that may be different from the default. You want to be careful not to remove the battery and lose these settings, but stuff happens.
- Disassembly is major surgery, do a full backup of the system. Programs that you have the original disks for can always be replaced, but any upgrades for those programs and any programs that have been downloaded from the Internet may or may not still be available. Bookmarks, e-mail addresses, phone and fax numbers, dial-up connections, DNS settings and networking protocols can be a real pain to replace. Even the best technicians cannot guarantee your data, so back it up. Also, in Windows9x, all the IRQ, I/O addresses, and DMA settings can be found (and printed) from the Device Manager in Control Panel. In Windows98 check out Start/Programs/Accessories/System Tools/System Information.
- Close all programs, shut down Windows, and turn off your computer. Then remove the cables from the back of the case.
- One other thing: you have to use a little common sense. Don't necessarily follow this information to the letter, it's only meant to be a guide. If you think it would be easier to remove some expansion cards before removing the drive bay, then do it. If you can better access the data cables after the drive is out, then do it that way. If it would be easier to disconnect the power cables and remove the power supply before accessing DIMMs or SIMMs …..
I think you get the point.
Removing the Cover
The standard way of removing tower cases used to be to undo 4-6 screws on the back of the case, slide the cover back about an inch and lift it off. Manufacturers are beginning to come up with trickier and more intricate methods of assembling these cases all the time. If there is no manual, then a little time taken for careful inspection may be in order. Here are some things to remember:
- Don't Force Anything. If it has to be forced, it will probably break. If there are no screws on the back of the case for the cover, check the plastic faceplate on the front. Some pry off to reveal screws or release levers (remember, careful inspection). If everything on the front has its own bezel around it (including the LEDs) then maybe the plastic front pops off (or maybe the case slides off the front).
- If you notice a separation between the sides and the top, then they must come off separately. My favorite ATX case allows you to remove two screws from the back, then slide the side panel to the rear an inch and remove it. The other side removes the same way. It's a good, solid, well built case.
- Make sure any screws removed are for the cover. You don't want to unscrew the power supply by accident and have it fall inside your computer. That's a bad thing.
- After the case is removed, place it in a safe place, where it won't get knocked of a table, kicked or stepped on and bent.
Removing Adapter Cards
- Again, documentation is very important. Yes, that 16-bit ISA card will probably work in any 16-bit ISA slot, but there may be a reason it's in that particular one. Document the type of card and which slot it comes from.
- Check the card for any cables or wires that might be attached and decide if it would be easier to remove them before or after you remove the card.
- Undo the screw that holds the card in place.
- Grab the card by its edges, front and back, and gently rock it lengthwise to release it. Do not wiggle it side to side as you can break the card, the slot, or the solder. Sometimes it helps to grasp the inside corner of the card with one hand and place a finger from the other hand under the associated port out the back of the computer to pry up the one end of the card.
- Once the card is removed, you may want to record any jumper settings you see, just in case one is accidentally dislodged. Try to store the card in an antistatic bag. If you don't plan on replacing the card then a cover should be installed over the slot opening.
Removing drives is not that difficult. They usually have a power connector and a data cable attached from the device to a controller card or a connector on the motherboard. CD-ROMs may have an analog cable connected to the sound card.
- The power will be attached using one of two connectors, a large Molex connector or a smaller Berg connector for the floppy drive. The Molex connector may need to be wiggled slightly from side to side while applying gentle pressure outwards. The Berg connector may just pull straight out or it may have a small tab that has to be lifted with a tiny flat screwdriver.
- The data cables need to be documented. Remember the pin one rule. Know where each one goes before you pull it out and record its orientation (which side is the stripe on, where is pin 1?). Pull data cables gently and carefully. In other words, don't yank them off, and pull level and in the direction of the pins.
- Now you need to do a little more inspection, can the entire drive bay be removed? Does that particular drive come out the back of the bay or does it slide out the front before the bay is removed. If a bay is removable, you may have to remove some screws or unclip a lever then slide the bay back and off. If the bay is not removable, there should be access ports on the other side of the case that allow for access to those screws (there should be, I've seen some that you just about have to remove the motherboard to access these screws). Now you can remove the screws and slide the drive out the back of the bay. If the drive slides out the front of the case, then remove the screws and gently slide it forward.
Removing the Memory Modules
Memory modules are one of the chips that can be damaged by as little as 30 volts. Be careful of ESD and handle them only by the edges. SIMMs and DIMMs are removed differently:
- SIMM - gently push back the metal tabs holding the SIMM in the socket. Tilt the SIMM away from the tabs to about a 45% angle. It should now lift out. Put each SIMM in its own protective bag.
- DIMM- There are plastic tabs on the end of the DIMM socket. Push the tabs down and away from the socket. The DIMM should lift slightly. Now you can grab it by the edges and place it in a separate antistatic bag.
Removing the Power Supply
- Make sure it's unplugged.
- All power connectors should be removed, including the connection to the motherboard and any auxiliary fans. Watch the little plastic tabs on ATX connectors (you'ld rather not break them). AT power supplies have a two piece power connector that may be labeled P-8 and P-9. Make note of the orientation. The black wires should be in the middle, black to black.
- Remove the connection to the remote power switch at the front of the case. Orientation of the colored wires at this switch is critical. If you remove them, make sure you document well, and during re-assembly plug the computer into a fused surge protector before turning it on (this could save your motherboard and components from melting if you've reconnected improperly). If you're putting the same power supply back, it's better to remove the entire switch and leave the connectors entact. The remote switch on an ATX form factor attaches to the motherboard.
- Remove the four screws at the back of the case and gently slide the power supply out of the case. While removing these screws, hold onto the power supply. You don't want it falling into the case.
Removing the Motherboard
- Document and remove all wire attachments to the motherboard. (Some of these have Pin 1 designations also.)
- Most cases have a removable panel that the motherboard is attached to. By removing a couple of screws the panel can be taken off and you can gain much better access to the motherboard. Again, a little investigation can save a lot of trouble.
- There is usually 2 or 3 screws holding down newer motherboards. Make sure you've got the right ones and remove them.
- Motherboards sit on plastic or brass standoffs that keep the traces and solder from touching the metal case and grounding out. Once the screws are removed you can lift the motherboard out. In other cases, the motherboard has to be slid horizontally towards the bottom of the case to unclip the plastic standoffs and then lifted out.
- Place the motherboard in an antistatic bag.