Note, Map, and Label
The first time you remove something from your computer chassis can be unsettling or even frightening. How can you, an unqualified technician, be expected to get everything put back when you're finished? Did this cable-thingy plug in here or over there? Did the whatsit plug in like this or like that? And what about this plug that doesn't plug into anything? Was it like that when I started or did I forget to hook something back up?
Don't get scared; get cautious. Caution is your friend.
Mapping the Layout
Take a moment (and a pad of paper) and sketch out the area of your system on which you'll be working. This might be just a relatively small area of the system (for example, if you're performing a RAM upgrade) or it might be the entire system (if you're pulling out and replacing the motherboard).
Deciphering the Layout
The manual that came with your motherboard probably has a schematic drawing that labels the major components of the motherboard. This can be very helpful when you're trying to determine things such as which IDE connector is the primary and which is the secondary or where the DIMM slots are.
Draw a map of the internals. On your map, note the position of the drives, which device plugs into what, where the cables run (what they go over or around), which slot each card is plugged into, and everything you see so you know how it all goes back together again. You might not know that the twisted red and blue wires are for the hard drive activity light, but if you know it connects to the two pins "over there" on the map, you'll be able to hook it back up correctly. Figure 3.5 shows a typical motherboard in a newer PC and the slots and connectors to which you connect the processor, RAM, sound cards, video cards, network cards, drives, and power supply. Your motherboard might vary somewhat, especially if you have an older system. But if you carefully note the location of each connection before disassembly, you'll be able to reassemble it. Also, before disconnecting each of the power plugs that connect your motherboard and drives to the power supply, be careful to note the position of the connectors. If any of the cables has a colored stripe (usually red) along one edge, be sure to note this when making your map so you can properly plug these back in when you are finished.
Noting All Connections
With some yellow stickies and ordinary cellophane tape, you can label and tag your computer's cards and cables as necessary while you work. Be sure to remove them all when you're done, though. Then, when you reassemble your system, you'll know that wire "A" connects to card "B" in the upper-right corner.
Tag each thing you unplug even if it's unrelated to what you're upgrading. Remember, space can be very cramped inside your system. For example, you might need to unplug the power connection and the controller cable for something such as the CD-ROM to get at the drive installed just above it in the chassis. Experience has taught us that it's easy to forget about things you disconnect while trying to get at the thing on which you want to work and on which you have your attention focused. If you forget to reconnect it, you'll power up your system after the upgrade only to find that something that was working before now appears broken. A yellow sticky on a loose power connector would have reminded you to reconnect the item.
Writing Down the Steps
Here's a trick that you should definitely use until you gain some experience with a particular hardware upgrade. Write down each thing you do, step by step. Say you're upgrading your old CD-ROM drive to a new CD-R/RW (Recordable/ ReWritable) drive. If this is your first attempt at upgrading this particular component, take the time to write down each step as you complete it.
Roadmap to Your Upgrade
Disconnect power lead to CD drive. Label A.
Disconnect ribbon cable to CD. Red stripe on cable toward open side of case. Label B. Usually a thin wire is running from the CD drive to the sound card. Disconnect from the CD. Label C.
Remove four screws (two on each side) of drive bay bracket holding CD drive in case.
Slide CD drive out through front of case.
Now you've got a road map of the upgrade procedure. When you install the new CD-R/RW drive, you can simply check off the steps in reverse order (as appropriate). This can be a lifesaver, so you should take the necessary additional time to do this whenever you are performing an upgrade you're unfamiliar with or when working on a system that's new to you. Don't assume that every chassis is laid out the same way.