Saturday, October 25, 2014

The basics

At some point, everyone should learn the basics of computer hardware.   As an advanced user, it can sometimes be frustrating to hear a non-technical user talking of buying a very advanced, expensive, laptop to do the same basic things they can do on a modern smartphone.   For a hardware technician like myself, it’s Important to know the details of the hardware of for obvious reasons, and knowing the details of many form factors and legacy components doesn’t hurt as well. 
So, in the spirit of education, let’s open up a desktop p.c. and take a look.





This is the basic ATX form factor.   ATX is the de facto standard for desktop PCs.    An important note before opening a desktop up yourself- take precaution!  Like any electrical device, it needs to be unplugged before its inner components are touched.   After unplugging, it’s recommended your wait a few seconds for the electrical current to die down before continuing.      Once inside, you can go start looking at key components.   Ideally, you’ll have gloves on to avoid static and be using tools without any magnetism to avoid damaging the components.  
Key Components
1.        Power Supply =Once inside, note the power supply at the top left.    There’s no need to open that up, unless you consider yourself an electrical specialist.    There are clear warnings that it can cause electrical shock.   There’s a time and place to replace a power unit, but for now leave it alone.
2.        Heat sink fan/CPU- To a beginner, it might seem strange that something as important as the central processing unit is a small chip buried underneath the fan.    It’s designed that way for a reason- the CPU can get very hot.  The heat sink is a spiked piece of aluminum (below the fan,
above the CPU) that absorbs the heat from the CPU and releases into the air for the fan to spread around.   If you take it apart, don’t neglect to put the heat sink back on.  It is critically important for the survival of your PC.    The fan explains itself.  It fans the heated air from the CPU to the vents on the desktop case to keep the unit cool.     Deep underneath it all rests the CPU.  It serves as the central interstate system for all the information being passed along the motherboard from the hard drive, RAM, GPU and chipset.  It’s rare to replace a CPU in my experience, but the important thing is to follow directions, using a processor that is compatible with your motherboard and socket type so as not to damage the metal teeth that hold it tightly in place.  There are too many socket types to list here, but looking up the motherboard name on a search engine will turn up the manufacturer’s website and a list of compatible processors.

3.       Video card is also called a GPU –Graphical Processing Unit.     Without it, your PC will only see very basic, blurry, shapes.    If you are familiar with safe mode, it boots without the GPU.    The GPU will look differently than the above picture from behind.  It screws into the back of the case, and will have your video connections, usually HDMI or digital in the newest computers.
4.       Hard Drive- You can think of the hard drive as the computer’s long term memory.  Your documents, programs, and the operating system itself reside on the hard drive to be retrieved as needed.
5.       Memory (RAM)   RAM stand for Random Access Memory.    The best way to understand it is too contrast it with the Hard Drive.   Each bit of information stored on a hard drive exists on a physical space on a spinning plate with the hard drive casing.    RAM is a stick directly integrated into the circuitry of the motherboard.    It can quickly read and write information and is used primarily to allow the computer to quickly juggle many tasks.  In practical terms, the more complex the needs of your computer (e.g. editing video with graphical effects) the more RAM is recommended.
6.       Motherboard.    This is the circuitry that connects all this together.   The board has all the connections for all the peripherals and slots to expand them.  The practical thing to know as a technician is that each make and model will have different peripherals that is compatible with depending on its and manufacturer.    A 2005 motherboard is not likely to be compatible with a high end gaming GPU and processor.

That’s it for today’s basic lesson.   These topics can be delved into much deeper.   I remember the study guide for my first A+ certification was 1100 pages.   Not all of that detail is necessary for most people.  But knowing the basic hardware in your PC will prevent you from getting lost in your future travels as a consumer or technician.