220-1101 Hardware and Network Troubleshooting Study Guide for the CompTIA A+ Core Series Exam

Problems with Storage Drives and RAID Displays

Storage devices include persistent storage such as storage drives and RAID storage. The most common causes of storage device problems are bad adapters, a bad or failing drive, or improper connection. You must be able to troubleshoot and diagnose problems with these systems based on a given scenario.

Common Symptoms

While a bad adapter and an improper connection are relatively simple to detect and test, symptoms of a bad or failing drive are more complicated. Below is a list of common symptoms of a bad or failing drive or RAID.

LED Status Indicators

Light-emitting diode (LED) status indicators are typically visible on storage devices. A blinking light typically indicates a busy drive, while a light that does not come on at all or stays solid may be an indicator of a problem. However, you need to look at the vendor-specific specifications for indicator lights since the indicator lights on one product may not have the same meaning as lights on another product, such as a RAID display with a light that only comes on when a problem is detected in the array.

Grinding Noises

A grinding noise originating from a storage device is a significant indicator of imminent failure in a motor or spindle within the device. This grinding sound can also be heard as squealing sounds or nails on a chalkboard. It is important to back up the affected drive immediately and replace the drive.

Clicking Sounds

A rhythmic clicking or ticking sound is an indicator of a drive that is in the process of failing. Once again, back up and replace the drive immediately.

Bootable Device Not Found

Upon bootup, a storage device is first detected by the BIOS/UEFI, and then the OS. The “Bootable Device Not Found” error can be an indicator of a complete failure to boot or a failure of the OS to be found. Check connection points and cables between the motherboard and the drive if BIOS/UEFI autodetection fails. If a proper connection does not resolve the issue, it may be a bad drive. If the BIOS/UEFI is able to detect the drive but is unable to detect the OS, the issue may lie in the master boot record (MBR).

Data Loss/Corruption

Data loss or corruption can be caused by a failing or full drive. To remedy the issue, first attempt to remove unneeded files or applications or defragment the drive. If this does not remedy the issue, you may attempt to format the drive and reinstall the OS. If the issue persists, the drive is most likely failing.

RAID Failure

Troubleshooting a RAID failure is similar to troubleshooting a single storage drive. First determine if the problem originates with a single drive or the system as a whole and proceed from there. Check the indicator lights on the RAID system for insight. Remember that the problem could originate from the type of RAID that is being employed.

S.M.A.R.T. Failure

Self-monitoring, analysis, and reporting technology (S.M.A.R.T.) is software installed on drives that monitors hard drive reliability and performance. S.M.A.R.T. metrics, while in theory useful for diagnosing and predicting drive failure, tend to be overly complicated and difficult to parse. One useful component of S.M.A.R.T. is the ability to create performance benchmarks that may prove valuable in diagnosing potential drive failures.

Extended Read/Write Times

Extended read/write times, like data loss/corruption, can be indicators of a failing or full drive. Troubleshoot this issue as you would data loss/corruption.

Input/Output Operations Per Second (IOPS)

Input/output operations per second (IOPS) refers to how many reads and writes a storage device can perform in a second and is listed on storage devices, such as NAS and RAID systems. A steadily declining IOPS may be an indicator of drive failure.

Missing Drives in OS

Missing drives in the OS may be indications of a connection issue or an improperly set up storage device. Troubleshoot missing drives by checking connections, checking the BIOS/UEFI for the enabled drive, finding the drive in disk management or disk utility, making sure the drive is prepared and partitioned properly, updating drive drivers, and checking for bad sectors, which may cause the OS to show the drive as unreadable.

Problems with Video, Projectors, and Displays

Consider this situation:

A call comes in to the help desk: The Chief Financial Officer has started a meeting with the “C” level officers (including the Chief Executive Officer) in your company, and the projector won’t power on. This has happened before and will happen again. What’s the next step?

Below are some of the more common symptoms to look for. Watch out, those projector bulbs can be hot!

Common Symptoms

When troubleshooting issues with video, projectors, and displays, there are some common symptoms that should be considered prior to escalation. Remember to always check the basics first.

Incorrect Data Source

An incorrect data source means that the input source for the viewing device and the input source selected for the computer are not the same. Viewing devices, such as monitors and projectors, can have multiple data ports on them, including HDMI, DisplayPort, or VGA.

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Physical Cabling Issues

Physical cabling can cause a wide variety of issues, such as no image being produced or an image that appears and then disappears. Visually inspect cabling for imperfections and switch out cables with known working cables to diagnose or rule out cabling issues.

Burned-Out Bulb

Burned-out bulbs are specific to projectors. Projector bulbs have a limited life. Replace the bulb to solve this issue.

Fuzzy Image

Fuzzy images can be caused by different problems depending on the display device. With a projector, check the focus mechanism. With an LCD screen, fuzzy images can be caused by external interference, cabling issues, or resolution settings.

Display Burn-In

Burn-in is when an image or image outline is still visible on the display. This is caused when images remain on the screen and become permanent parts of the display.The only solution is to replace the display.

Dead Pixels

Dead pixels are the result of pixels that do not fire. This issue is typically related to the hardware or the monitor itself. Replacement of the display is usually necessary to correct it.

Flashing Screen

Often, a malfunctioning screen will either flash or flicker. A flickering screen is most likely caused by a failing backlight. Replace the backlight. With a flashing screen or a screen that turns on and off, the most likely cause is a bad connection cable.

Incorrect Color Display

With an LCD monitor, an incorrect color display is most likely caused by a failing controller board, which is responsible for color mapping. Another cause of an incorrect color display may be the connection cable or the pins on the display device itself.

Audio Issues

Many display devices today have built-in audio. To troubleshoot any audio issues, first check that the audio is not muted and the audio volume is up. On the computer itself, make sure that the appropriate audio output is selected.

Dim Image

Dim images can be caused by either an issue with the display device itself, generally caused by a failing backlight, or the computer being set to a low brightness setting.

Intermittent Projector Shutdown

Intermittent projector shutdowns are most commonly caused by overheating. Check to ensure proper airflow and unimpeded fans and filters.