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Troubleshooting Modems and Communications Tools

This section describes how to solve problems with installing modems, making connections, and using applications to access the modem. Windows 98 provides a troubleshooting aid for modems in online Help. Windows 98 captures call control information in a log file, for troubleshooting connections.

Try using online Help for troubleshooting before trying the steps included in this section. In addition, a general modem diagnostic tool is located in the Modems option in Control Panel. It provides information about each modem or COM port that has been configured on the computer.

This section also includes troubleshooting information for ISDN.

To use the Modems Diagnostics Tool

  1. In Control Panel, double-click Modems, and then click the Diagnostics tab.
  2. In Diagnostics Properties, click Driver to find out which communications driver is installed. For these applications, the driver should be Comm.drv. If a different driver is listed and you are having problems with using Win16-based applications, the driver is probably the cause.
  3. In Diagnostics Properties, click More Info to make sure Windows 98 can communicate with the modem. Clicking this button causes Windows 98 to send commands to and read responses from the modem, and then to display information about the modem and its COM port.

    The Port Information box displays the following information:

    The Modem Information box displays the modem’s responses to various AT commands that Windows 98 previously sent to it. Some modems return a response that indicates their make and model. This can help you select the correct modem if the Install New Modem Wizard did not detect it correctly. Notice that many modems return ERROR for some AT commands. This means that the modem does not support that particular AT command.

Tip

You can access the Windows 98 Modems Troubleshooter by clicking Help.

Windows 98 helps you identify modem problems by recording modem commands and responses in a text file, as described in "Setting Modem Properties" earlier in this chapter. This log file always contains a log of the most recent call, and, if the Append a Log File option is checked, it records successive calls in the same log file. The file name consists of the name of the modem as displayed in the Modem applet of the Control Panel with a .txt extension. For example, if the modem is called Modem1, the name of the log file is Modem1.txt.

Correcting Problems with Modem Installation

This section describes situations that can interfere with installation of a modem and how to fix them.

Modem detection is incorrect.

If Windows 98 detects your modem as a Standard Modem Type or incorrectly detects its make and model, use the Change button in the Install New Modem Wizard to make a different selection. However, if you manually select an incorrect type, your modem may not work with Windows 98 communications features. If this happens, double-click Modems in Control Panel, remove the modem, and then add it as one of the Standard Modem Types.

Windows 98 will use your modem with its factory default settings if you have configured it as a Standard modem. The modem will make optimal high-speed connections with Windows 98 communications features. However, you will not be able to adjust some of the modem’s settings, such as those for speaker volume and cellular protocols.

You can also specify a location to load the drivers from by inserting the disk that came with your modem, and from the Install New Modem Wizard, click the Have disk button. Select your modem from the list.

Your Racal modem does not respond.

If you have a Racal modem, do not use detection in the Install New Modem Wizard. Instead, click Don’t detect my modem, and then pick one of the Standard Modem Types. If you have already run detection and your modem is not responding, turn the modem off and then back on again.

Your Minitel modem (France) does not connect.

Some modems may not be able to connect to French Minitel in HyperTerminal if you use the Windows 98 default settings.

Check your modem manual for a command that will enable your modem to connect in V.23 modulation to Minitel.

To reset your modem to connect to French Minitel

  1. In Control Panel, double-click Modems, click the name of your modem, and then click Properties.
  2. Click the Connection tab, and then click Advanced.
  3. In the Extra Settings box, type the correct command.
Modem detection may start AutoRun CDs.

On some computers, running modem detection may start the CD AutoRun application.

PC Card Power Management Modem not found or not ready.

When PC Card Power Management is enabled, some PC Card modems require an extra delay before they are ready. If you encounter this with your PC Card modem, the symptom is that it may not work when you try to use it, but it works if you try again right away.

To increase the delay, use the following procedure.

Caution

Before modifying any registry values, always back up your system. See "Backing Up and Recovering the Registry" in Chapter 31, "Windows 98 Registry." If you use Registry Editor to change values in the registry, you will not be warned if any entry is incorrect. Editing the registry directly by using Registry Editor can cause errors in loading hardware and software, and can prevent users from being able to log on to the computer.

  1. Click Start, click Run, and then type regedit.
  2. Go to the \HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\Modem subkey.
  3. Click the key for the modem that you are trying to use.
  4. To add a key in the root of the modem, click the Edit menu, and then point to New.
  5. Click DWORD Value, and create a DWord named ConfigDelay.
  6. Set the value equal to "3000" for a three-second delay.
The Install New Modem Wizard detects the modem as a Standard Modem Type.

This does not indicate a problem. Rather, it means that Windows 98 was unable to detect the exact make and model of a modem. Most communications applications work correctly with the standard modem; that is, you can successfully make connections using the modem’s factory default settings. However, advanced control of some features, such as speaker volume, error control (for example, V.42 protocol), and compression (for example, V.42bis protocol) will be disabled in the modem’s properties.

If you do not want to use the standard modem, you can run the Install New Modem Wizard to select a specific type of modem similar to the modem you are using. If you specify another, similarly named model from the same manufacturer — for example, if you configure the modem as a Practical Peripherals PM9600HC when a Practical Peripherals PM9600FX modem is actually installed — Windows 98 usually treats the models as being identical, and the specified configuration will probably work well.

To determine whether other modem models are compatible with the one you are using, check the modem manual. Many modems are compatible with Hayes, Microcom, Rockwell, or U.S. Robotics models.

You can also use the disk that came with the modem to install the modem drivers by clicking the Have disk button in the Install Wizard.

The Install New Modem Wizard did not detect any new modems.

Take the following steps:

If the Install New Modem Wizard still does not detect a modem, there is probably a problem with the port, the cable, or the modem itself. Try the modem with another computer, if possible.

You cannot install a PC Card modem.

If you are using a PC Card modem for your Dial-Up Networking connection to the Internet and have not yet installed the modem, you may have to enable Windows 98 PC Card socket support before running the Internet Setup Wizard.

To enable PC Card socket support

  1. Click Start, point to Settings, and then click Control Panel.
  2. Double-click the PC Card icon to start the PC Card Wizard, and then follow the instructions on your screen.

If you cannot find the PC Card icon, you may need to install the PC Card drivers.

The Install New Modem Wizard does not detect PC Card modem drivers.

If the Windows 98 PC Card drivers are loaded, Windows 98 should automatically detect and configure a PC Card modem when it is installed. Use the Add New Hardware option in Control Panel to check the configuration of a PC Card socket driver.

If the Windows 98 PC Card drivers are not being used, the modem card must be configured as a COM port before the Install New Modem Wizard can detect and configure it as a modem.

To detect and configure a PC Card modem when Windows 98 PC Card drivers are not used

  1. Configure the modem according to the instructions that came with your original PC Card driver software.
  2. Run the Add New Hardware Wizard to detect and configure the card as a COM port.
  3. Run the Install New Modem Wizard to detect and configure the card as a modem.

Correcting Problems with Modem Connections

This section describes basic steps for troubleshooting modem connections and explains specific communications errors or problems and how to correct them.

The modem will not dial or will not answer.

If your modem is not set up correctly, communications features might not function properly. The following procedures list steps in verifying the correct operation of your modem and the Windows 98 communications subsystem.

Because some communications programs designed for Windows 3.1 install incompatible driver files, which can cause COM ports and modems to stop working, start by verifying that the correct Windows 98 files are being loaded.

To verify that the required communications files are present

  1. Verify file sizes and dates of Comm.drv and Serial.vxd in the System directory against the original versions from the Windows 98 floppy disks or compact disc.
  2. Confirm that the following lines are present in System.ini:
    [boot]
comm.drv=comm.drv
[386enh]
device=*vcd
  3. To revert to the default communications drivers for Windows 98, delete communications port entries in Device Manager.
  4. Run the Add New Hardware Wizard in Control Panel to detect and install the Windows 98 drivers.

Note

Windows 98 does not load the Serial.vxd driver in System.ini. Rather, Windows 98 loads it on demand by using the registry. Also, there is no corresponding file for the *vcd entry in System.ini. This is an internal file built into Vmm32.vxd.

To verify the modem configuration by using the Modems option in Control Panel

  1. In Control Panel, double-click Modems.
  2. In General properties, verify that the manufacturer and model for your modem are correct. If not, you might have changed the modem and failed to reconfigure it. In this case, run the Install New Modem Wizard to detect the modem, and confirm it with the current registry configuration.
  3. If your modem does not appear in the list of installed modems, click Add, and then select the appropriate modem.
  4. If the manufacturer and model are not correct and are not available from the list, try the Hayes-compatible option or the Standard Modem Types driver option, set to the maximum speed supported by the modem. Click OK.
  5. Try removing any other modem entries in the list to eliminate any conflicts.

To verify that the modem is enabled by using the System option in Control Panel

  1. In Control Panel, double-click System.
  2. Click the Device Manager tab, click a modem from the list, and then click Properties.

To verify that the port is correct by using the Modems option in Control Panel

  1. In General Properties, click a modem, and then click Properties.
  2. In General Properties for that modem, verify that the listed port is correct. If it is not, select the correct port. Click OK.
  3. Select the Diagnostic tab, highlight the modem, and then click the More Info button. This will verify the system can communicate with the modem.

To determine if a serial port’s I/O address and IRQ settings are properly defined by using the System option in Control Panel

  1. Click the Device Manager tab, click Ports, and then click a specific port (such as COM2).
  2. Click Properties, and then click the Resources tab to display the current resource settings (IRQ and I/O) for that port. To find the correct settings, consult the modem manual.
  3. In the Resources properties, check the Conflicting Devices List to see if the modem is using resources in conflict with other devices.
  4. If the modem is in conflict with other devices, click Change Setting, and then click a Basic Configuration that does not cause resource conflicts.

Note

Interrupt (IRQ) conflicts are common when using a modem on COM1 and a serial mouse on COM3. Usually, COM1 and COM3 ports use the same IRQ, meaning that they cannot be used simultaneously on most computers. The COM2 and COM4 ports may also use the same IRQ. If possible, change the COM3 or COM4 port to an IRQ setting that is not in conflict.

Also, some display adapters (especially S3, 8514A and ATI mach8) have an address conflict with COM4 ports. You can work around this by using another COM port or replacing your display adapter.

Click System in the Control Panel, and then click Device Manager to see how Ports (COM and LPT) are currently assigned.

To check the port settings by using the Modems option in Control Panel

  1. Click a modem in the list box, and then click Properties.
  2. Click the Connection tab to check the current port settings, such as bits per second (speed), data bits, stop bits, and parity.
  3. Click Advanced to check error control and flow control. If you are using Win16-based applications, turn off these advanced features.
  4. Verify the UART type.

    Data transmission problems can occur if a speed greater than 9600 is selected on a computer not equipped with a 16550 UART, or when performing other tasks during a file download. If problems or errors occur during transmission, try lowering the speed. Attempting to use speeds greater than 9600 on computers equipped with 8250 or 16450 UARTs will probably result in dropped characters.

To check the modem speed by using the Modems option in Control Panel

  1. Click a modem in the list box, and click Properties.
  2. In General Properties, check the speed to make sure it is not set too high for either the modem or computer. Lower speeds might work, especially when using an older, slower computer.
  3. Click Only Connect At This Speed if it is not already selected.

Tip

To optimize communications performance, you can set the speed higher if your computer has an 80486 or a Pentium processor.

To disable hardware flow control if your modem cable does not support it

  1. In Control Panel, double-click Modems, click a modem in the list box, and then click Properties.
  2. Click the Connection tab, and then click Advanced.
  3. If a check appears in the Use Flow Control check box, click the box to clear it.

To remove VxDs from other vendors that might be interfering with modem operation

The initialization (dialing) string is improper for the modem.

If the modem will not pick up the line and dial, the problem might be due to an improper initialization string. Typically, the manufacturer’s recommended dial command string is loaded from the corresponding modem INF file; however, if your modem driver is not available and you select a compatible modem, the dial command string might not work correctly. Try using the Standard Modem Types option, and retest the modem dialing the selected number.

The modem repeatedly drops the connection.

Take the following actions:

The COM ports remain in Device Manager after the modem has been removed.

After you have installed an internal modem and assigned it to a COM port that does not physically exist on your computer, the port appears in Device Manager. After removing this adapter, you might also need to manually remove the port in Device Manager, as described in Chapter 24, "Device Management."

You are unable to dial international calls.

Windows 98 allows you to set specific modem properties that assist you when making international calls over your modem. You set these properties in Dial-Up Networking, Dialing Properties, and in Modems Properties.

To check location and calling card settings

  1. In Control Panel, double-click Telephony.
  2. In the My Locations properties, verify that your calling location and calling card settings are correct.

To disable dial tone detection if your modem fails to detect a dial tone

To increase the time between dialing if connections are taking a long time

To control modem dialing manually, see "Dialing Manually" earlier in this chapter. To display a terminal window to type AT commands before or after dialing, see "Displaying the Terminal Window" earlier in this chapter.

Correcting Problems with Modem Access Through Applications

This section describes troubleshooting problems with applications using a modem.

You cannot send or receive binary files by using HyperTerminal.

Take the following actions:

You cannot dial with Phone Dialer.

Take the following actions:

Win16-based applications cannot access the modem, but MS-DOS-based or Windows 98–based applications can.

Make sure the communications driver for Windows 3.1–based applications in the System.ini file is Comm.drv. Some applications replace this driver for various reasons.

MS-DOS-based applications cannot access the modem (especially a PC Card modem), but all Windows-based applications can.

Take the following actions:

Errors occur during MS-DOS-based applications communications sessions, especially file transfers.

Increase the COMxBuffer setting in the [386Enh] section of System.ini. The default value is 128 bytes.

Correcting Problems with Integrated Services Digital Network

To connect through ISDN, you must specify a telephone number for each channel you request when requesting more than two. For example, if you request three channels, you must specify three telephone numbers (separated by colons, with no spaces). Insert the telephone numbers in the Phone number box in the Basic tab, as you would when adding, editing, or cloning any other entry — for example:

555-1234:555-1234:555-5678

If you request four channels, specify four telephone numbers — for example:

555-1234:555-1234:555-5678:555-5678

Note

If there are more channels specified than telephone numbers given, the extra channels will attempt to use the last number. For this reason you can use one number for a two-channel call, because ISDN lines normally support two channels each. However, some ISDN telephone companies require a unique number for each channel. Check with your ISDN provider.

ISDN fails to connect.

When you dial through ISDN and fail to connect, the error message "No answer" appears. This message means one of several things may be wrong:

Check for any of these potential problems. When you have solved the problem, redial the number.

Your ISDN adapter can support only a single channel.

Not all ISDN adapters can support more than one channel. Read the documentation included with your adapter to identify whether your ISDN adapter can support Multilink PPP.

Your ISDN line is not set up for dual-channel connections.

When you have your ISDN line installed, you may need to specify to your ISDN provider that you need support for two channels on your line. This is not always the default configuration from an ISDN provider.

Your ISDN adapter settings are not correct.

With most ISDN adapters that can support Multilink PPP, you must change the settings to enable dual-channel capabilities. Use the documentation included with your adapter to identify which settings to use for Multilink PPP. Then you can change the settings using the following steps.

  1. In Control Panel, double-click Modems.
  2. Click the ISDN adapter you are using, and then click Properties.
  3. Click the Connection tab, and then click Advanced.
  4. In the Extra Settings box, type the dual-channel settings for your ISDN adapter. You can find these settings in the documentation for your adapter.
The two ISDN channels are connected to different access boxes.

Internet access numbers sometimes have more than one access box to handle a large number of incoming calls at once. Sometimes, when you connect with two channels, the channels get separated into two different access boxes. This situation is called straddling. When straddling occurs, your second channel might not make a connection. And in some cases, your adapter might not make a connection at all. If this happens, you must wait and try your connection again later.

The telephone numbers for your adapter are not configured correctly.

ISDN lines usually come configured with two telephone numbers. When you use dual-channel ISDN, your adapter uses only one telephone number. The second number might be the reason your second line is not connecting. This problem is especially common with the 3Com Impact adapter running firmware version 2.02. If you think the second telephone number might be the problem, try reconfiguring your adapter to use only one of your ISDN numbers.

Drivers are not supported in Windows 98.

ISDN drivers from the ISDN version 1.0 Accelerator Pack are not supported in Windows 98. Contact your ISDN adapter’s manufacturer if you require updated drivers. For a list of known vendor drivers that work with ISDN 1.1 included with Windows 98, see http://www.microsoft.com.

Additional Resources
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