CompTIA A_ Certification All-In-One Exam Guide, Seventh Edition - Michael Meyers [85]
Figure 5-64 Removing an old fan
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CAUTION Using a new fan when you replace a CPU is a good idea even if the old fan works with your new CPU. Fans get old and die too.
Inserting a PGA-Type CPU
Inserting and removing PGA CPUs is a relatively simple process; just don’t touch the pins or you might destroy the CPU. Figure 5-65 shows a technician installing a Sempron into a Socket 754. Note that the pins on the CPU only fit in one orientation. These orientation markers are designed to help you align the CPU correctly. Although the orientation markers make it difficult to install a CPU improperly, be careful: Incorrectly installing your CPU will almost certainly destroy the CPU or the motherboard, or both!
Figure 5-65 Orienting the CPU
To install, first lift the arm or open the metal cover. Align the CPU, and it should drop right in (Figure 5-66). If it doesn’t, verify your alignment and check for bent pins on the CPU. If you encounter a slightly bent pin, try a mechanical pencil that takes thick (0.9mm) lead. Take the lead out of the mechanical pencil, slide the pencil tip over the bent pin, and straighten it out. Be careful! A broken CPU pin ruins the CPU. Make sure the CPU is all the way in (no visible pins), and snap down the arm or drop over the metal cover.
Figure 5-66 CPU inserted
Now it’s time for the CPU cooler. Before inserting the heat sink, you need to add a small amount of thermal compound (also called heat dope). Many coolers come with heat-sink compound already on them; the heat-sink compound on these pre-doped coolers is covered by a small square of tape—take the tape off before you snap down the fan. If you need to put heat dope on from a tube, know that it only takes a tiny amount of this compound (see Figure 5-67). Spread it on as thinly, completely, and evenly as you can. Unlike so many other things in life, you can have too much heat dope!
Securing heat sinks makes even the most jaded PC technician a little nervous (Figure 5-68). In most cases, you must apply a fairly strong amount of force to snap the heat sink into place—far more than you might think. Also, make certain that the CPU cooler you install works with your CPU package.
Figure 5-67 Applying thermal compound
Figure 5-68 Installing the fan
Testing Your New CPU
The next step is to turn on the PC and see if the system boots up. If life were perfect, every CPU installation would end right here as you watch the system happily boot up. Unfortunately, the reality is that sometimes nothing happens when you press the power button. Here’s what to do if this happens.
First, make sure the system has power—we’ll be going through lots of power issues throughout the book. Second, make sure the CPU is firmly pressed down into the socket. Get your head down and look at the mounted CPU from the side—do you see any of the CPU’s wires showing? Does the CPU look unlevel in its mount? If so, reinstall the CPU. If the system still does not boot, double-check any jumper settings—messing them up is very easy.
As the computer starts, make sure the CPU fan is spinning within a few seconds. If it doesn’t spin up instantly, that’s okay, but it must start within about 30 seconds at the least.
The Art of Cooling
There was a time, long ago, when CPUs didn’t need any type of cooling device. You just snapped in the CPU and it worked. Well, those days are gone. Long gone. If you’re installing a modern CPU, you will have to cool it. Fortunately, you have choices.
OEM CPU Coolers OEM heat-sink and fan assemblies are included with a retail-boxed CPU. OEM CPUs, on the other hand, don’t normally come bundled with CPU coolers. Crazy, isn