220-1201 Hardware and Network Troubleshooting Study Guide for the CompTIA A+ Core Series Exam

Issues with Mobile Devices

Mobile devices are here to stay. For the purposes of the CompTIA A+ exam, the term refers to laptops and smaller devices. The main difference is they are smaller—sometimes much smaller—than other devices. Compact and portable, mobile devices can be much tougher to troubleshoot than conventional devices. Your company policy will dictate the level of repair you will be required to perform on these. If the device is personally owned, you might not be required to work on it.

Keep in mind that the questions about this area will begin with a scenario. Below are some fairly common symptoms and corresponding questions you should ask with regard to mobile devices. Ensure you have a very clean workspace and sufficient lighting prior to undertaking a major repair.

Poor Battery Health

Poor battery health can be evident by checking to see if a device works when physically plugged into a power source or if a fully charged battery drains very quickly with normal usage, within 30 minutes, for example. Overheating can also be an indicator of a failing battery. For a battery that will not hold a charge at all, replace the battery. With a laptop that holds a poor charge, you can attempt to perform a battery calibration before resorting to a battery replacement. With a smartphone, you can try to drain the battery completely and recharge it before resorting to replacing the battery.

Swollen Battery

A swollen battery is a battery that is visibly distended. Swollen batteries can have numerous causes including old age, overheating, gas buildup, overcharging, and physical damage. If a swollen battery is suspected, turn off the device immediately and replace the battery.

Broken Screen

A broken screen will have to be replaced if the break is severe enough to affect functionality.

Improper Charging

Most mobile devices have a charging indicator light or icon of some sort. While it is rare for the indicator to fail, it can happen. To check for this issue, plug the device in with a known working charger and see if the indicator is on. Improper charging is typically caused, however, by a connection issue, such as a damaged cable or the use of an aftermarket cable that is not fully compatible with the device.

Poor/No Connectivity

When troubleshooting poor or no connectivity, begin by checking to make sure the appropriate connectivity method is on, such as Bluetooth® or wireless. If the connection method is enabled, check the signal strength of the connection. Poor connectivity can be caused by too much distance between the sending and receiving devices.

Liquid Damage

Liquids can cause significant issues in a mobile device. If liquid damage is suspected, turn off the device immediately and let the device air dry. A laptop with significant liquid damage can be disassembled and cleaned using demineralized water and a lint-free cloth.

Overheating

Overheating can cause a device to shut down or not function properly. If overheating is suspected, shut down the device immediately and allow it to cool. To reduce the likelihood of overheating, ensure that the device is allowed proper airflow and keep all flow components clean and clear of dust and debris.

Digitizer Issues

To address digitizer issues on a laptop, you should go into the settings of the device and attempt to recalibrate the digitizer. If the digitizer cannot be calibrated or fixed, you may be able to work around the issue by using a mouse and keyboard for input. With a mobile phone, the only method for fixing the digitizer is to fully power off the device and power it back on. If this does not fix the issue, the screen will need to be replaced.

Physically Damaged Ports

With a physically damaged port, the only solution is to replace the port.

Malware

Malware is any malicious software designed to disrupt the usage of, cause damage to, or gain unauthorized access to an infected device. Antivirus and antimalware software can identify, isolate, and remove most malware as well as defend against incoming malware. A firewall can also be used to help prevent infection.

Cursor Drift/Touch Calibration

Cursor drift is most commonly caused by a faulty pointing stick. You can move the input device around in an attempt to resolve the issue, or you can attempt to recalibrate it. Recalibration can also be used to remedy faulty calibrations on touch screens.

Unable to Install New Applications

The inability to install new applications has multiple potential causes. Common causes include a lack of available memory, an outdated or incompatible OS, or incompatible underlying hardware such as the processor or display. Check available memory and application requirements prior to installation.

Non-Functioning Stylus

A non-functioning stylus may be an indicator of an issue with the stylus itself or the receiving device. If the stylus type is passive, the cause may be interference from a screen protector, a faulty digitizer, or an incompatible device or software, some of which require a specific type of stylus for functionality. With an active stylus, non-functionality may also be caused by stylus battery issues, a degraded tip, software issues, or connection issues.

Degraded Performance

Performance degradation on a mobile device often manifests as reduced speed, usability, and device responsiveness. Possible causes of performance degradation can be hardware-related, such as a lack of available storage space or RAM, overheating, or a faulty battery. Performance issues can also be logical, such as an outdated OS, malware infection, network connectivity issues, or an excessive number of open tabs or applications.

Network Issues

Given a scenario, you will need to troubleshoot common wired and wireless network problems. Networks are at the heart of today’s computing. A failure in network access is likely to prevent users from doing their work or accessing necessary information. It needs to be addressed effectively. Below are some fairly common symptoms and corresponding troubleshooting steps and questions you should ask with regard to networking and connectivity issues. Some basic troubleshooting tactics remain constant: check physical cables, the connection, and for speed or duplex mismatch first.

Intermittent Wireless Connectivity

Intermittent connectivity occurs when wireless connectivity appears and disappears. Intermittent connectivity is the most difficult to troubleshoot. When troubleshooting intermittent connectivity, try to narrow down the issue by addressing latency, jitter, port flapping, and slow network speeds.

Slow Network Speeds

Slow network speeds on a wired connection are mostly due to an overload of the network. Solutions include adding a switch or creating virtual local area networks (VLANs) with switches. A wireless connection with slow speed can also be caused by overload to the wireless access point (WAP) or wireless router. Distance from the WAP can also cause slow network speeds.

Limited Connectivity

Limited connectivity is a state in which a device is connected to the network but can’t reach outside of the local network. Even some local resources might be unreachable.

• For Wi-Fi networks, this is frequently caused by an incorrect password. Try reconfiguring the Wi-Fi connection with the correct password.

• For wired Ethernet networks, the issue is usually due to the device not getting an IP address from the Dynamic Host Configuration Protocol (DHCP) server, or it’s due to having a static IP address that doesn’t match the router network configuration. You will have to consider various factors:

  • Does the device have the IP address configured manually?
  • Is the default gateway configured correctly?
  • Does it match the IP address of the router on the network?
  • For dynamic IP addresses, does the device get an IP address assigned?
  • Is it in a valid range on the same network as the router on the network?

Jitter

Jitter is variable latency (or delay). With both wired and wireless devices, jitter can be caused by overloaded networks. A poor cable connection can also cause jitter on a wired device.

High Latency

High latency can cause the connection to appear intermittent. Troubleshoot high latency as you would intermittent connections.

Poor Voice over Internet Protocol (VoIP) Quality

Intermittent network connectivity or a slow network can cause poor VoIP quality. Most managed systems running VoIP have a priority setting for different streams of networks. To increase VoIP quality, rank the VoIP connection as a high priority.

Port Flapping

Port flapping causes intermittent connectivity when a switch opens and closes a port very quickly. To troubleshoot port flapping, check cables, the connection, and the duplex. Another place to check for port flapping is the error logs on the switch to see at which layer the error occurs. Also, reseat the small form-factor pluggable (SFP) connector. If this does not remedy the issue, switch to a known working SFP.

External Interference

External interference is caused when an external device interferes with the wireless signal of a WAP or wireless router. External devices that can cause interference include radio signals, physical barriers, microwaves, motors, or fluorescent lights. If external interference is suspected, change the positioning of the WAP or the external device if possible.

Authentication Failures

Network authentication failures are generally due to either user problems or network problems.

• User-caused authentication failure is most commonly caused by credential typos, such as wrongly entered usernames or passwords. Expired passwords or devices that do not meet the security requirements of the network may also cause user-related authentication failures.

• Network-related authentication failures may be more complex and can be caused by network congestion, issues with the network hardware, firewall configurations, or interference, among other issues.

Intermittent Internet Connectivity

Intermittent internet connectivity can manifest as an unstable connection or highly fluctuating speeds. Intermittent connectivity may be due to issues experienced by the internet service provider (ISP), such as an outage or equipment malfunction, or due to issues with the LAN, such as network congestion, hardware problems, interference, or logical problems (e.g., outdated drivers or configuration issues).

Printer Issues

Given a scenario, you’ll need to be able to troubleshoot printers. Although a lot of information is passed digitally in the modern work environment, printers still have their uses in offices, and IT professionals need to know their way around troubleshooting and maintaining them. Inkjet and laser are the most common printer types in offices. Other less common printer types are impact and thermal.

Printers can be either directly connected to a computer for local use or shared over a network. Below are some fairly common symptoms, corresponding troubleshooting steps, and questions you should ask with regard to printers and printing issues.

Lines Down the Printed Pages

Lines on the printed page are usually caused by ink residue. Follow the printer’s cleaning procedure. This may include physically cleaning the internal parts of a printer or a cleaning process that can be triggered by the printer’s software. First, try printing a test page and see if streaks appear there too. Sometimes, streaks are caused by the scanning part of a copier, and therefore they aren’t a printing problem.

Garbled Print

A garbled print may mean a software or connection issue. Check to ensure the correct drivers are installed, the printer is firmly connected with a good cable, and there is enough RAM free on the printer.

Paper Jams

There are many reasons for frequent or sporadic paper jams. The reasons can be categorized as related to the paper or to the printer hardware.

Paper Issues

Ensure that the paper size and weight used are as recommended by the printer’s manufacturer. Try using a new, dry pack of good-quality paper. Don’t load too much paper at once. Bend the stack of paper to separate sheets before loading.

Printer Hardware Problems

If the problem is not with the paper, then the printer hardware needs to be examined. Check to see if the printer has been maintained per the manufacturer’s recommendations. Some printers have a page counter and recommendations on replacing specific internal parts to prevent paper jams. If the jams are frequent, check for broken parts in the feeding path.

Faded Prints

When the prints are faded, check the toner or ink levels first. You can replace the cartridges with new ones of known good quality. Also, check the printing settings to see if, for instance, there are any ink-saving settings enabled that may reduce the amount of ink or toner used.

Paper Feeding Issues

If there is a failure to feed paper, follow the same troubleshooting steps as for a paper jam. A multipage misfeed can be caused by separation pad issues or sticky/damp paper.

Multiple Prints Pending in Queue

If pending jobs are building up, there may be specific errors that will direct you to the proper troubleshooting steps, such as issues with toner, paper, or access. A backed-up queue may also be due to spooler issues. Restart the spooler service. Then, try disabling the spooler and printing directly to the printer with no queueing.

Speckling on Printed Pages

Speckling, small marks, or defects on printed pages are common with frequently used or older laser printers. This is often caused by spilled toner or a crack or chip in the EP drum. To fix this issue, clean or replace the roller. With an inkjet printer, speckling is often caused by dust or residue in the printer. Clean the printer with compressed air. If the problem persists, it may be a leaking cartridge. Replace the cartridge.

Double/Echo Images on the Print

Echo images can happen on laser printers due to a broken cleaning blade or bad erasure lamps. Try replacing the toner cartridge or the erasure lamps.

Grinding Noise

Impact printers can produce grinding noises due to a damaged stepper motor. You will have to replace the motor.

Finishing Issues

Many laser printers have finishing options, such as collation, stapling, and hole punching. Issues with the finisher are typically resolved with thorough cleaning.

Staple Jams

Problems with the stapling process are typically caused by malfunctions in the finisher. Check to ensure there are staples in the mechanism and that it does not have any jams.

Hole Punch

Problems with the hole punch process require the same process as the stapler. Ensure there are no blockages to the hole punch mechanism.

Incorrect Page Orientation

Page orientation refers to the side of the paper that is configured to be the top of the page. There are two types of orientation, portrait and landscape. Portrait orientation places the short edge of a standard sheet as the top of the page and the long edge as the sides, while landscape orientation places the long edge of the paper as the top with the short edge as the sides. Incorrect page orientation is most likely caused by the settings within the printer or software. Ensure that the printer is set to print with the correct orientation.

Tray Not Recognized

A printer not recognizing a tray, which is the compartment holding the paper supply or printing material, can be caused by misconfigurations in the paper settings, physical problems such as paper jams or an improperly seated tray, or logical issues such as driver misconfigurations or outdated firmware.

Connectivity Issues

Printer connectivity issues can be due to power, hardware, or logical problems. Power problems include an unplugged printer or a printer that is not powered on. Hardware issues include bad cables, ports, or physical components. Logical considerations that can cause connectivity issues include outdated drivers and firewall or network misconfigurations. When connecting a printer wirelessly, interference or physical obstructions may also cause connectivity issues.

Frozen Print Queue

A frozen printer queue occurs when a print job is received but is unresponsive and not printing or allowing for deletion. A frozen print queue can be caused by problems with the printer, such as low ink or toner levels, paper jams, or hardware failure. Faulty network connections, software conflicts, and issues with the print service can also cause a frozen print queue.