Chapter 20

Hardware and Network Troubleshooting

The following CompTIA A+ Exam 220-802 objectives are covered in this chapter:

• 4.2 Given a scenario, troubleshoot common problems related to motherboards, RAM, CPU and power with appropriate tools.
  • Common symptoms
  • Unexpected shutdowns
  • System lockups
  • POST code beeps
  • Blank screen on bootup
  • BIOS time and settings resets
  • Attempts to boot to incorrect device
  • Continuous reboots
  • No power
  • Overheating
  • Loud noise
  • Intermittent device failure
  • Fans spin – no power to other devices
  • Indicator lights
  • Smoke
  • Burning smell
  • BSOD
  • Tools
  • Multimeter
  • Power supply tester
  • Loopback plugs
  • POST card
• 4.3 Given a scenario, troubleshoot hard drives and RAID arrays with appropriate tools.
  • Common symptoms
  • Read/write failure
  • Slow performance
  • Loud clicking noise
  • Failure to boot
  • Drive not recognized
  • OS not found
  • RAID not found
  • RAID stops working
  • BSOD
  • Tools
  • Screwdriver
  • External enclosures
  • CHKDSK
  • FORMAT
  • FDISK
  • File recovery software
• 4.4 Given a scenario, troubleshoot common video and display issues.
  • Common symptoms
  • VGA mode
  • No image on screen
  • Overheat shutdown
  • Dead pixels
  • Artifacts
  • Color patterns incorrect
  • Dim image
  • Flickering image
  • Distorted image
  • Discoloration (degaussing)
  • BSOD
• 4.5 Given a scenario, troubleshoot wired and wireless networks with appropriate tools.
  • Common symptoms
  • No connectivity
  • APIPA address
  • Limited connectivity
  • Local connectivity
  • Intermittent connectivity
  • IP conflict
  • Slow transfer speeds
  • Low RF signal
  • Tools
  • Cable tester
  • Loopback plug
  • Punch down tools
  • Toner probes
  • Wire strippers
  • Crimper
  • PING
  • IPCONFIG
  • TRACERT
  • NETSTAT
  • NBTSTAT
  • NET
  • Wireless locator
• 4.8 Given a scenario, troubleshoot, and repair common laptop issues while adhering to the appropriate procedures.
  • Common symptoms
  • No display
  • Dim display
  • Flickering display
  • Sticking keys
  • Intermittent wireless
  • Battery not charging
  • Ghost cursor
  • No power
  • Numlock indicator lights
  • No wireless connectivity
  • No Bluetooth connectivity
  • Cannot display to external monitor
  • Disassembling processes for proper re-assembly
  • Document and label cable and screw locations
  • Organize parts
  • Refer to manufacturer documentation
  • Use appropriate hand tools
• 4.9 Given a scenario, troubleshoot printers with appropriate tools.
  • Common symptoms
  • Streaks
  • Faded prints
  • Ghost images
  • Toner not fused to the paper
  • Creased paper
  • Paper not feeding
  • Paper jam
  • No connectivity
  • Garbled characters on paper
  • Vertical lines on page
  • Backed up print queue
  • Low memory errors
  • Access denied
  • Printer will not print
  • Color prints in wrong print color
  • Unable to install printer
  • Error codes
  • Tools
  • Maintenance kit
  • Toner vacuum
  • Compressed air
  • Printer spooler

By now, you’ve probably gotten the feeling that troubleshooting is really hard. To be clear, it definitely can be. With all of the integration between software applications and hardware components, it can be challenging to understand where one stops and the other starts or how their interoperation affects one another. To top it all off, you’re probably going to be working in an environment that requires you to understand not just one computer but a network full of workstations, servers, switches, routers, and other devices and how they play nice together. Situations will arise that make even the most experienced technicians shake their heads in confusion.

The best way to tackle any problem, as we talked about in the previous chapter, is to take a systematic approach to resolving it. This applies to the software and security issues we covered in Chapter 19, “Troubleshooting Theory, OSs, and Security,” as well as the hardware and networking ones we’ll talk about here. Troubleshooting becomes a lot easier if you follow logical procedures and develop a little bit of experience.

Before we get into the details of specific problems, remember that in order to troubleshoot anything, you need to have a base level of knowledge. For example, if you’ve never opened the hood of a car, it will be a bit challenging for you to figure out why your car won’t start in the morning. If you’re not a medical professional, you might not know why that body part hurts or how to make it feel better. In the same vein, if you don’t know how data is stored and accessed on a computer, it’s unlikely you’ll be able to fix related computer problems. So, before you get too heavy into troubleshooting, make sure you understand how the systems you are working on are supposed to function in the first place!

Because this chapter is at the end of the book, we’re going to assume that you’ve read all of the other chapters, including the troubleshooting steps outlined in Chapter 19. Therefore, we’re not going to get into a lot of detail about how things work—it’s implied that you know those details by now. (If you’re still not certain, this book is a great reference manual!) Instead, we’ll talk more about what happens when things don’t work the way they’re supposed to: what signs to look for and what to do to fix the problem. The first part of this chapter will cover key internal hardware components. After that, we’ll look at issues specific to laptops and printers and then finish off the book with a section on network troubleshooting.