A+ Core 2 (220-1102) Cram Notes

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4. Troubleshooting

4.4 Given a scenario, troubleshoot common video and display issues

1. Monitors accumulate very high static charges and need to be handled very carefully. Before attempting any repair, it is imperative to discharge any accumulated charges on the monitor. You can use a jumper, one end of which is grounded, and touch the other end of the jumper wire to the anode of the monitor. While doing so, ensure that you are not in direct contact with the jumper wire or the anode. You can use a screw driver or a nose pliers with rubber handle for this purpose. A "POP" sound can be heard when the static charges accumulated on the anode lead getting grounded through the jumper wire. Remember, that if you get in contact with the static charge, it may lead to severe burns or even fatal accident!

2. Never wear a wrist strap when working on monitors. Monitors contain very high voltages, sometimes fatal to human, even when the power is turned off. If you are wearing wrist strap, the human body work as a conduit to discharge the electric charge.

3. When you are installing a different SVGA monitor, it is unlikely that the new monitor has the same capabilities as the old one. As a result, the image on the screen may not be readable. In such instances, change the video resolution to Standard VGA before installing the new monitor. You can change the resolution appropriately after the image on the screen is readable with the new monitor. It may also be necessary to load appropriate device driver, if you are installing a different display adapter.

4. The most probable cause that the screen is dumping garbled characters is that the communication settings are not correct. Check the speed, parity, start/stop bits etc. If the serial port parameters are correct, then you need to check the cable, such as straight/cross cable and the pin connections.

5. The problems such as video card, network card, and modem card can be resolved by booting to Safe Mode. While in Safe Mode, troubleshoot the problem.

4.5 Given a scenario, troubleshoot wired and wireless networks with appropriate tools

1. You need to memorize the following port addresses before attending the exam.


Address (in hex)













Floppy Controller


Hard Drive Controller, 16 bit, ISA


2. If Microsoft Windows Firewall is blocking a port that is used by a service or by a program, you can configure the Windows Firewall to create an exception. Windows Firewall may be blocking a program or a service if the following conditions are true:

  • Programs do not respond to a client's request.

  • Client programs do not receive data from the server.

3. NBTSTAT This utility displays current NetBIOS over TCP/IP connections, and display NetBIOS name cache.

4. NETSTAT Displays protocol statistics and current TCP/IP connections since the server was last booted.

5. TRACERT Used to determine which route a packet takes to reach its destination from source.

6. IPCONFIG Used to display Windows IP configuration information.

7. NSLOOKUP This utility enables users to interact with a DNS server and display resource records.ROUTE Used to display and edit static routing tables.

8. Network is not configured with WINS server. WINS server resolves the NetBIOS names to IP addresses. The network need to be configured with WINS (or LMHOSTS file on each computer) for NetBIOS name resolution.

9. If all the nodes on the network have been disconnected still if the switch port is blinking rapids even in the absence of any data, it is very likely that the switch port or the switch is bad.

10. Running a command like “ping” or “ipconfig” will open the command screen. However, the command screen closes soon after the execution of the command. If you intend to observe the results of any such command, you need to open the DOS screen by going to Program Files | Accessories | Command Prompt.

11. When doing over the network installation, the most likely causes for failure are:

  • The domain controller may not be up and running. You need to ensure that the domain controller is running.

  • The username and password may not be correct. You need to have appropriate access rights to join a domain. Ensure that you have appropriate access rights and that you have typed in correct username and password. Note that the passwords are case sensitive in Windows 2000.

  • Ipconfig: Displays TCP/IP configuration values, including IP address, subnet mask, and default gateway.

  • Ping: This command can be used to verify whether the target ip address or host name is present. You need to specify the target IP address or host name.

  • route: Displays and manipulates route information.

  • Tracert: Determines the route packets take to reach the specified destination.

13. The most important thing to do when a network card is replaced is to update the NIC driver. Without this, the network card may not work. The NIC speed is limited by the peer device. If it is connected to a 1Gbps switch port, then it will transmit at rated speed. However, note that if the cable does not support 1 Gbps speed, you may need to replace the cable also. Usually, the network devices fall back to mutually acceptable speeds.

14. If a user complains that he is not able to connect to his Windows 7 computer remotely the reason may be Windows Firewall restricts communication between your computer and the Internet, you might need to change settings for Remote Desktop Connection so that it can work properly.

  • Open Windows Firewall by clicking the Start button Picture of the Start button, and then clicking Control Panel. In the search box, type firewall, and then click Windows Firewall.

  • In the left pane, click Allow a program or feature through Windows Firewall.

  • Click Change settings. Administrator permission required If you're prompted for an administrator password or confirmation, type the password or provide confirmation.

  • Under Allowed programs and features, select the check box next to Remote Desktop, and then use the check boxes in the columns to select the network location types you want to allow communication on.

  • Click Ok

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