troubleshooting in modem

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Modems allow computers to send and receive data over a phone line by converting digital computer data to analog audio phone signals and vice versa.

Points of Failure

Modem Model - Points of Failure
Points of Failure

•        Hardware

On desktop systems, modems are extension cards. There are thumbs down integrated modems on Dell desktop systems. On a hardware level, modem
troubleshooting is akin to troubleshooting other extension cards: Reseat the modem, swap the modem to a uncommon PCI slot, and remove supplementary
components (like extension cards and peripherals).

On current portable systems, modems occur as modem daughter cards (MDC). MDCs join to their own slot on the PCI automobile. They can be reseated. They
cannot be stirred to mini-PCI or other slots on the PCI automobile. On grown-up Dell portables, modems be inflicted with occur as mini-PCI cards, PC cards, and
integrated items on the logic board. Modems be inflicted with lone or two RJ-11 phone jacks. A phone cord connects the modem to the phone jack in the
customer's household.

•        Software

Like other extension cards, the modem driver should be installed. Recently installed programs can interfere with the modem. Startup applications listed in
MSCONFIG can cause problems with the modem.

Modems furthermore require special settings in Windows.

•        Home/Office

The modem is connected with an RJ-11 cable to a phone jack in the customer's household. Components outside the notebook surrounded by the customer's
household can affect the modem.

•        External World

After the modem connects to the phone jack in the customer's household, the indicate goes through the phone arrangement to the ISP (Internet Service Provider).
Many factors in the phone arrangement and ISP can affect the modem's performance. These points of failure are outside of both your control and the Dell
warranty support boundaries. Many modem issues cannot be resolved through standard Dell Hardware Warranty Support. To keep up customer satisfaction, sort
out the following:
O         Set appropriate expectations.

O         Provide technical and most likely explanations.

O         Ensure with the intention of the customer has the looked-for in rank to make the come forth resolved through Dell On Call, their ISP, phone company, or
third-party software vendor.


The more you understand modem troubleshooting and the tools unfilled pro you to aid, the better you will be able to resolve problems and take up customer

****** fax sw can keep the modem permanently engaged************

Internet Service Providers

Some customers be inflicted with doubtful perceptions on the function of the Internet Service Provider. A hardly any customers could not be aware with the
intention of they need an ISP. The Internet Service Provider should provide settings like:

•         The dial-up phone digit.

•         User first name and password.
•        IP Configuration pro linking the ISP's arrangement and the internet. The ISP typically uses DHCP to configure IP addresses.

If the modem can make a dial tone but cannot join, the conundrum is probably with the ISP, or surrounded by the settings supplied by the ISP.

Functional versus Performance Issues

Most modem issues fit into lone of two categories, functional and performance, with the following differences:

•         With functional issues, the modem is not detected, not installed, or cannot make a dial tone. Functional issues are ordinarily caused by hardware, drivers,
or settings.

•       With performance issues, the modem gets a dial tone. The modem tries to dial made known and get on to a connection. The modem cannot get on to a
connection, cannot stay connected, or is gradual. Performance issues are ordinarily caused by settings or by factors outside the notebook, such as low-quality
phone shape. Usually the modem and driver are functioning by the book.

The procedures pro troubleshooting functional issues are very uncommon from procedures pro troubleshooting performance issues.


Functional issues are ordinarily caused by lone of the following:

•        The modem is not detected or installed by the book.

•        The modem cannot access a COM haven. A COM haven is a resource used by a modem.

•        The modem is not connected to a phone line with a skilled dial tone.

If the modem can make to a dial tone, the following are ordinarily real:
•        The modem facility.

•        The modem driver is accurately installed.

Most functional issues can be diagnosed with Modem Helper, if it is unfilled.


The generally vital indicator of functional issues is the dial tone. If the modem gets a dial tone, you sort out not be inflicted with a functional come forth.
Troubleshoot as a performance come forth.

•        Error Messages

Windows will ordinarily produce an miscalculation message as:

O        The modem cannot be accessed.

O        The COM haven cannot be accessed.

•        Device Manager

Device Manager is ordinarily a skilled indicator of whether the modem is detected and installed by the book. Errors in Device Manager sort out not necessarily
mean a driver conundrum. A modem may possibly be inflicted with a resource conflict or be fit to disabled. Inside rare instances, a modem driver will appear to be
OK in Device Manager and still not bring about. Removing and reinstalling the driver will typically resolve this conundrum.

Connecting to the Phone Line

To bring about, the modem should be attached to a standard analog phone line with a habitual dial tone. Problems could be caused by:

•        Phone Line - Don't overlook the obvious. The phone jack in the customer's household has to be inflicted with a dial tone.
•       Modem Jack - Most modems be inflicted with two RJ-11 phone connectors: Lone "line in" from the wall jack, now and again labeled "telco," and lone pro
a phone handset. Switching these shape will cause approximately modems not to dial even though the customer can aid the attached handset.

•        Call Messaging Services - Most call messaging services consent to users know with the intention of a message is recorded by producing a distinctive
tone with the intention of modems sort out not recognize. One way to bypass this is to uncheck the option Wait pro dial tone previous to dialing in the Modem

•      Home/Office Phone Equipment - Other hardware (phone handsets, other modems, fax apparatus, and that.) on the phone line (especially linking the
modem and the wall jack) can cause interference, keeping the modem from dialing.

•        Digital / PBX shape - Most modems will not bring about on digital or PBX shape. These types of shape are uncommon in homes, but are often found in
offices and college dormitories.

COM Ports

A COM haven is a resource looked-for by the modem. Sometimes modems will fail with an miscalculation message correlated to the COM haven (Could not
commence COM haven; COM haven is unavailable or in use). Usually this earnings with the intention of approximately other attention is holding the COM haven.
The solution can be as unadorned as a reboot. Sometimes you will be inflicted with to clean up the Start Up background (MSCONFIG). Other persistent problems
could require reinstalling the modem or searching the Knowledge Base pro a solution.


Modems are very susceptible to destruction. Lightning strikes virtually the customer's family can hurl power surges through the phone shape or power line. These
can destruction the notebook and especially the modem.

Modems can be damaged as the power goes rancid in the customer's household. When the power comes back on, here are often power surges with the intention
of can destruction electronics. Frequently this sort of destruction is visible on the modem itself. Burn inscription or dark yellowing on the modem (especially at once
behind the phone jack) indicate modem destruction.

Damage is not covered under the Dell warranty.
A Badly Burned Modem

Modem Helper

Modem Helper can diagnose most functional issues. It can also fix some issues. It can reinstall drivers. It can suggest ways to fix errors. Below is a brief
description of what Modem Helper does.

        Hardware Detection - Modem Helper scans both the PCI bus and the Registry to detect the presence of a modem and its model to detect:
             o Physical Issues - poor seating or potential bad modem.
             o Nonsupported, Non-Dell, or Multiple Modems.
             o Mismatch between Registry and actual Modem.
        Driver Verification - Modem Helper uses the modem's .inf file (the information file for the driver) to check correct driver file and registry entries. If a
         problem is found, Modem Helper can reinstall the driver.
        COM Port - Modem Helper will try to open the COM port assigned to the modem. If it cannot (usually because another program is using it), it will suggest
         changes to the user.
        Dial Tone - Finally, Modem Helper tries to detect a dial tone using the modem.

If it is available, Modem Helper should be used with all functional issues. DSN Decision Trees help you use Modem Helper. Even with Modem Helper, you will
have to perform some basic troubleshooting. If Modem Helper cannot detect the modem, you will have to perform basic hardware troubleshooting.

For current modems, the drivers are installed by Modem Helper. If Modem Helper is deleted or corrupted, customers can download drivers from the Dell support
site. Sometimes you can send the customer a new copy of the Modem Helper disk. Older modems came with modem driver disks. If customers no longer have
this disk, they can download the drivers from the Dell support site.

    CE TIP:
    Diagnostic software takes much of the guesswork out of the support calls. Efficient identification and resolution of the customer's hardware issue promotes a
    positive Hardware Warranty Support experience.

If the modem gets a dial tone, most likely the hardware and software supported by the Dell warranty is good. The problem is most likely caused by settings
supplied by the ISP, or by conditions in the telephone network outside the customer's house. The job of the Dell technician is to:

        Verify that the hardware and software supported by the Dell warranty works. Demonstrate it when possible.
        Educate customers. Explain the most likely cause of the issue. Suggest to customers who they may contact for help.

The Dial-Up Process
                   Dial-Up Process                                                                       Notes

                                                        User hears dialing. Usually a progress window shows that the modem is dialing. The window will
The Modem dials.
                                                        usually list the number.
                                                        Usually the user will get a Connecting message in the progress window.

                                                        May get a message that the modem cannot reach the ISP or that the line is busy. May hear operator
The phone line is answered.                             message.

                                                                The dial-up phone number may be wrong.
                                                                The ISP may be experiencing too much traffic or may be having problems.

                                                        User hears a scratchy sound with one or more bounce sounds. This is the sound of the modems
                                                        establishing a connection and the connection speed.
Handshake - The modem tries to establish a stable
connection with the ISP's modem.
                                                        If the modem has trouble making a stable connection, the sounds may go on for a while with multiple
                                                        bounces. This is usually caused by problems in the telephone network.
                                                        No more sounds from the modem. A window shows that the modem is connected. The connection speed
Connection established.
                                                        is set.
                                                        If modem is connected but the user has errors browsing the Internet, it may be caused by IP settings or
Customer browses Internet.
                                                        ISP network problems. It could be a Firewall issue.
Speed Issues

Slow modems are a common complaint by customers.

        The Download speed is the speed that the modem loads files (web pages, email, files, etc.) through the network.
        The Upload speed is the speed the modem sends information (emails, files, screen commands, etc.) through the network.

The term throughput refers to the speed at which data is actually transferred between the ISP and the end user. Throughput determines how fast web pages load
and files download from the Internet. To check throughput, you can download files from the Internet. An average throughput of 4.0 KB/sec or better is pretty good.
Throughput Shown at Download

Speed vs. Stability

The modem signal can become distorted or corrupted when it travels through the phone line. This is caused by noise, static, or other conditions on the phone line.
Modems can handle some distortion in the signal. This slows the modem speed down. The more distortion in the signal, the slower the modem speed. If
there is a lot of noise on the phone line, the connection will be slow. The connection can become unstable and disconnect.

During the handshake, the modem tries to make a stable connection. During this time, the modem tries to connect at the fastest speed possible. If the signal is
poor, then the connection will be slow. The speed of the modem may go up or down after it has connected. The modem adjusts to different conditions on the
phone line. This is called retraining.
Several factors can reduce the quality of the customer's phone line:

        Problems at the ISP.
        Problems in the telephone network.
        Problems with the phone wiring in the customer's house.
        Fax machines, other modems, answering machines, phones, and other hardware connected to the phone line inside the customer's house.
        Long phone cords. A six-foot or less phone cord is recommended. The longer the cord, the more chance for interference.
        Peripherals, like speakers, that have strong electrical magnetic fields around the phone cord.

Modem standards determine the maximum modem speeds. The table below lists modem standards and speeds. These speeds are theoretical. In practice,
modems do not reach these speeds.

    Standard                       Maximum Theoretical Download Speed                                        Maximum Theoretical Upload Speed

V.34               33 Kbps                                                                    33 Kbps

X2 / Kflex         56.6 Kbps                                                                  33 Kbps

V.90               56 Kbps                                                                    33 Kbps

V.92               56 Kbps                                                                    48 Kbps

Limitations of 56K Standards

Many factors limit the speed of the modem. To start, the United States Federal Communications Commission (FCC) restricts modem speed on phone lines to
around 53K to reduce heat across the phone network.

The 56K standards rely on certain conditions. The ISP must use a digital modem attached to a digital phone line. Most of the path from the ISP to the home user is
digital. The signal is converted from digital to analog near the end user (usually on a neighborhood level). There must be one and only one Digital to Analog (D/A)
conversion between the ISP and the End User.

Each time an analog signal is converted to digital, opportunities for inaccuracy are introduced. For some homes or offices, there are multiple D/A conversions
between them and the ISP. In these cases, 56K transmissions are not possible. The modem reverts to V.34, which will result in a maximum connect speed of 33.6
Other Speeds

In addition to throughput, there are other ways to define modem speed. These "speeds" are largely irrelevant to troubleshooting. They rarely affect how fast
customers can browse the Internet or download a file. However, some customers may confuse them with modem performance.

       Connection speed is the speed of the connection just after the handshake. The connection speed is shown on the Connection Properties window.
        Customers are aware of it.

           Connection speed is not a good measure of throughput. The speed of the connection may change up or down during the session. The connection
           speed remains the same on the Connection Properties window. Throughput is dependent on other factors in addition to speed, such as data

       Internal speed is the speed that the system communicates with the modem. This is defined in the Modem Properties.
Internal Modem Speed

Customers may have trouble connecting to their ISP. Find out when the problem occurs:

       After the modem dials, but before the handshake - The dialup properties are probably wrong. The telephone number for the ISP may be incorrect.
       During the handshake the modem fails to connect - Most likely noise in the communication will not allow a stable connection.
       After the handshake - The modem connected. It worked.
            o The session may have been disconnected for some reason, including instability.
            o The modem may be connected. The customer doesn't realize it because they cannot get email or browse the Internet. These problems could be
                 caused by other factors like improper IP or firewall configuration.

Troubleshooting and Educating

You will not be able to resolve most performance issues. You can:
        Demonstrate that the modem is working.
        Educate the customer on likely reasons for the problem.
        Provide an option for getting the issue resolved (like calling the ISP or phone company for support).

Modem Helper

Modem Helper generally does not resolve performance issues. Modem Helper can demonstrate to customers that the modem is working.

Remove Unnecessary Hardware

Ask customer to remove unnecessary hardware that could be causing line noise. This includes peripherals (printers, speakers, etc.) and phone equipment (fax
machines, line splitters, other phones, etc.)

Move the Computer

If the customer is willing, move the computer to another room or another house. If the problem is a poor quality phone line, the modem will usually work better
from another location. Sometimes the phone line in another part of the house is better.

Connect to Another Number

If the modem cannot connect to the ISP, the ISP phone number might be wrong. Have the customer dial another number. Set up a new dial-up connection in the
Network Connection applet. This is found in Control Panel. Have the modem dial the customer's cell phone or another known number.


HyperTerminal is a Windows utility. HyperTerminal allows you to access the modem directly. With it, you can bypass the modem settings and dialup programs.
You can use HyperTerminal to dial a number or to change modem settings. HyperTerminal is difficult to use without instructions. DSN will direct you on how to use

     CE TIP:
     When troubleshooting a modem, you may be testing several possibilities to find an area of failure. Keep your customer informed of what you are doing and
     why you are doing it. This displays professionalism and helps the customer to know you are not stuck.
Summary and Key Points

The Modem Troubleshooting module introduced you to modem technology, common modem problems, and modem troubleshooting.

Key Points

       Modems allow computers to send and receive data across a phone line by converting digital computer data to an analog audio phone signals
        (MOdulation) and vice versa (DEModulation).
       In addition to the computer hardware and software, modem points of failure are in the customer's house, in the telephone network, and at the customer's
        Internet Service Provider (ISP). Because of this, many modem issues cannot be resolved by Dell technicians.
       Most modem issues fit into two categories:
             o With Functional Issues, the modem is basically not working. It cannot receive a dial tone. Functional issues are often caused by hardware or
             o With Performance Issues, the modem can receive a dial tone. The connection is slow, locks up, or is unstable. Performance Issues are rarely
                  caused by the computer hardware or drivers.
       Points of Failure for functional issues include
             o Hardware - modem, system board, seating, BIOS, nonessential peripherals, etc.
             o Software - drivers, nonessential applications, viruses, etc.
             o Phone Line - jack in the customer's house, phone cord, connections, etc.
             o COM Port - A resource used by the modem.
       Functional issues may be caused by electrical damage to the modem.
       Performance issues are often caused by incorrect settings or by poor quality phone lines.
   If the modem dials but does not reach the ISP, the problem is probably with the ISP or the dial-up properties.
   When phone lines are noisy, the modem must correct for errors. The modem is slower when it corrects for errors. If the phone lines are very noisy, the
    connection will be unstable. Sometimes the modem will disconnect.
   Noise can occur at any point on the phone lines between the computer and the ISP.
   Customers can reduce sources of noise in their homes by:
          o Using a short phone cord.
          o Moving peripherals and other electronic devices away from the phone cord.
          o Taking fax machines, other phones, other modems and any other devices off the phone line.
   Many performance issues cannot be resolved by Dell technicians. The Dell technician should verify the Dell components and educate customers.

                   A customer has a factory-installed V.92 modem in their system. But when they attempt to dial up, they always get a stable
                   connection at 33.6K. They have contacted their ISP, and the ISP responded that their systems are capable of V.92. The
           1       customer doesn’t understand why the speed is not 56K. Which of the following statements is good information to give the

                                               A V.92-capable modem is only capable of 33.6K speeds; the customer will be unable to
                                          connect at 56K with their current modem.

                                                 All lines between your location and the ISP may not be capable of supporting 56K speeds;
                          this is normal behavior.

                                The customer will need to contact their ISP again to have them enable full V.92 access on
                         their account.

                               The modem should always be connecting at 56K; therefore, the modem is faulty and will
                         need to be replaced before any speed improvement can be obtained.

    A customer calls from his workplace, saying that he brought his system from home into work. He connected the modem to
2   the wall jack, but could not get a dial tone. The modem worked fine at home. Which of the following should you check first?

                                Have the customer check to see if the phone line at his workplace is digital, instead of

                                Have the customer remove the modem driver from Safe Mode, and then reinstall it using the
                         latest driver on

                                The customer needs a work account from their ISP.

                                The modem should be replaced, because it worked fine previously with the system at home.

    A customer calls in saying that he just received his system, but he cannot find any reference to the modem. You check the
3   Device Manager with the customer, and there is no Modem category, and no listing in Other Devices. Which item in the
    following list could be a Point of Failure?
                                 A line splitter

                                 Missing modem drivers

                                 The proximity of the video card to the modem

                                 An unseated modem

    A customer has a surge protector connected between his modem and his phone jack. After a large storm passed over his
4   area, he is no longer able to get a dial tone with his modem. Which item in the following list should you try first?

                                 The computer should be opened and the modem should be checked for damage.

                                 The phone line between the modem and the surge protector should be swapped out.

                                 The phone line between the surge protector and the phone jack should be swapped out.

                                 The surge protector should be removed and the modem connected directly to the phone

    A customer complains that their connection rates are below 14,400bps, and very unstable. The customer has another phone
5                                                                                                                  41512
    in the room coming from the same wall jack. Which item in the following list could be a Point of Failure?
                              A line splitter.

                              An unseated modem.

                              Missing modem drivers.

                              The proximity of the video card to the modem.

    A caller reports that he ran Modem Helper and received the following Result Code: 9. Should his modem be replaced?
6     41513

                              No. This code indicates an problem with the Modem Helper program files not the modem.

                              No. This error message indicates a problem with the installed Operating System.

                              No. This error message indicates a problem with the modem firmware.

                              Yes. This error message indicates a problem with the installed drivers.

    Your customer cannot connect to the Internet. Modem Helper shows that the hardware is functioning and getting dial tone.
7                                          41514
    What is the next most likely cause?

                              Disconnected phone line

                              Driver problems
                                    ISP problems

    8     To run Modem Helper, the user must be logged in __________.

                                   As a member of the printer group

                                    As the system administrator or a member of the administrator’s group

                                   With a connection of 56kb or more

                                   With a DSL connection

          What is the maximum allowable cable length between the phone jack and the modem, according to V.9x specifications?
    9      41517

                                   Four feet

                                    Six feet

                                   Twelve feet

                                   Twenty feet

Block B       Choose all that apply type questions
1   What does Modem Helper test? Choose all that apply.

                                            Hardware detection

                                            Software configuration

                                            Software validation
                                            Modem Performance

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