White Box Troubleshooting 101

Every PC you encounter will seem to have its own personality—and an enigmatic, stubborn one at that. Sometimes you can pinpoint a problem quickly and correct it in a snap. But other times, even though you know you've done everything possible to overcome a problem, the darned box simply refuses to cooperate.

Don't fret. In this TechBuilder Recipe, I'll take you through the three major areas involved with analyzing and fixing any PC you're likely to come across: hardware, software, and security.

Whether you're just getting started as a professional system builder, or you're a serious whitebox hobbyist, this Recipe is for you. Let's get started.

Five Steps for Troubleshooting System Hardware

First, let's look under the hood of a typical system and identify five of the most common hardware problems a system builder will encounter. Some of these steps will serve as reminders to take care of the "no-brainer" stuff, such as checking a PC's connections. Others--such as problems with an optical drive subsystem--will take more careful consideration. We'll start with the simplest, easiest-to-fix problems, and then move along to the more complicated ones.

1. Power supply or voltage selection switch: The most basic element of any electronic device is electrical power, of course, and that's certainly true for a PC. Yet there'll be times when you think you've done everything a technician is supposed to in order to get a PC up and running--and yet, for some strange reason, there's no juice getting to the system's components.

   It's easy to jump to the conclusion that you've got a bad power supply. But odds are the power supply is fine. Instead, check all the connections. Sounds simple, but it's often an easy step to overlook. A typical power supply is depicted here:

   
   

   If, after checking the connections, you still can't get the system to boot, check the system's voltage selection switch and make sure it is set correctly for your country. Since most power supplies originate out of the Far East, it's not uncommon to find the voltage selection switch has been set to 220 volts. If you're in the U.S. or other country that runs at 110 volts, you'll need to reset the switch.

2. Power-on configuration: Another gremlin you'll occasionally come across occurs with the “power-on configuration" of the motherboard. Modern system boards control the power-on functionality of any system. That's most often accomplished by connecting a jumper wire from the case power switch to a connector on the system board, as shown here:

   
   

   Also, make sure the system board and all components on the system are properly grounded by attaching all mounting screws and mounts.

3. Video, RAM or CPU: If power is not the problem, then the next likely candidates to check are video, RAM, and CPU. You'll know you're having problems with any of these three areas, as ailments are indicated by a series of audible beeps.

   Most motherboards have an integrated piezo electric speaker that beeps a certain number of times (it's different for each machine) when there is a problem of some kind. That beep count can be your best clue to drilling down on a hardware problem.

   Simply refer to the motherboard's documentation to locate exactly which problem corresponds to the beep count you hear. But note, in some instances you may need to physically connect an external speaker to the motherboard (via a jumper) to actually hear the telltale beeps. Let's look at each function separately:

   • Video: For troubleshooting video troubles, first swap out the video card and replace it with another. If the swap fixes the problem, you've found your culprit. However, there are other elements that could make video unworkable. First, make sure the video card is seated properly—that's another often-overlooked no-brainer. Next, be aware that certain video cards require additional power; so make sure the power supply is connected properly, and also make sure the power supply is the one required for the system. Here's a look a one common video card:

     
     

   • RAM: Some systems have "on board" video, in which a video controller is integrated directly onto the motherboard. In these cases, a lack of video can be attributed to a jumper or switch that is not set properly to enable the onboard video. This is usually a very simple fix. But when RAM is the root of the problem, often the modules have not been inserted properly. The first step is to reset the modules and check for any bent edge connectors. Next, check the system documentation to ensure you're using the correct RAM. Finally, be aware that for some systems, modules need to be paired together to make the system bootable. Here's a typical set of RAM modules:

     
     

   • CPU: CPU-related problems can be more complex to solve. If you're dealing with a faulty CPU, you usually will need to trash the chip. Be careful when installing the CPU, because many processor problems are due to plain old incorrect installation. For example, be careful not to damage the pins. A common chip (with inherent pins) is shown here:

     
     

     Also, because modern CPUs are expected to power a myriad of parts on a system, adequate cooling is critical. Running a CPU without a heat sink or a fan can damage the processor in as little as a few seconds! Here's a look at a fan that has been correctly installed:

     
     

4. Hard drive cables: If you encounter the dreaded “operating system not found" or “inaccessible boot device" error messages, then the problem is likely related to either the hard drive or the optical drive subsystem. The biggest culprit here is often (believe it or not) a reversed cable! Some cables or drives are not “keyed" properly, or they are incorrectly notched, meaning they're simply installed backwards. Happily, by merely by correcting the cable, this problem will be solved. A typical cable—notched correctly—is shown here:

   
   

5. Checking the BIOS: Another system “gotcha" concerns the BIOS settings. In other words, the default bios settings are set wrong! Some manufactures default to "IDE drives disabled" or other such settings that can prevent an attached drive from being recognized. The simplest solution is to check the BIOS and make sure it's set correctly. But for new installs, you should also check the “boot order," as usually you'll need to boot off the optical drive (CD/DVD) to install an operating system. That should be set to boot first, as shown here: