FRITZ!Box 7490 – Service - Knowledge Base

FRITZ!Box 7490 – Service

"Power" LED flashes

As soon as you connect your FRITZ!Box to your DSL line, the FRITZ!Box establishes a connection to your DSL provider's exchange. This can take up to 10 minutes. During this time, the "Power" LED on the FRITZ!Box flashes. As soon as the DSL connection has been established, it stays lit.

This guide shows you how to resolve the following errors:

  • The FRITZ!Box's "Power" LED flashes continuously.
  • The FRITZ!Box does not establish a DSL connection.

The following error message is displayed in the event log of the FRITZ!Box:

  • "DSL not responding (no DSL synchronization)"

Note:The configuration procedure and notes on functions given in this guide refer to the latest FRITZ!OS for your FRITZ!Box.

Simply proceed as described below. After each measure, check whether the problem persists.

1 Error occurred after updating FRITZ!OS

If the error occurred directly after a FRITZ!OS update, follow the instructions given in the following guide:

2 Checking the event log of the FRITZ!Box

  1. Click "System" in the FRITZ!Box user interface.
  2. Click "Event Log" in the "System" menu.
  3. If the message "DSL is available (DSL synchronization exists with [...] kbit/s)" is displayed in addition to the message "DSL not responding", follow the instructions in our guide FRITZ!Box reports that the DSL connection drops frequently.

3 Making sure that the DSL line is supported

4 Selecting the DSL standard in the FRITZ!Box

The following step is only necessary if you are using the FRITZ!Box on an ADSL line:

  1. Click "Internet" in the FRITZ!Box user interface.
  2. Click "DSL Information" in the "Internet" menu.
  3. Click on the "Line Settings" tab. If the tab is not displayed, enable the Advanced View first.
  4. In the "Annex Settings" section, select whether your FRITZ!Box is connected to a DSL line that uses Annex A or Annex B.

    Note:Your DSL provider can tell you whether your DSL line uses Annex A or Annex B. In Germany, all ADSL lines use Annex B.

  5. Click "Apply" to save the settings.

5 Resetting the interference resistance

Set the control for interference resistance to "Maximum Performance" since otherwise you will not be able to establish a DSL connection with some DSL lines:

Note:The interference resistance should only be changed if your DSL connection is occasionally interrupted, for example due to brief disturbances on the DSL line.

  1. Click "Internet" in the FRITZ!Box user interface.
  2. Click "DSL Information" in the "Internet" menu.
  3. Click on the "Line Settings" tab. If the tab is not displayed, enable the Advanced View first.
  4. Click the "Reset Setting" link.
    • Now the interference resistance is automatically set to "Maximum Performance".

6 Checking the DSL Line and Cabling with the DSL Line Test

Performing the DSL line test

  1. In the FRITZ!Box user interface, click "Contents" on the bottom left of the page and then "FRITZ!Box Support".

    Fig.: Links to "Contents" and "FRITZ!Box Support" in the user interface

  2. Click the link "DSL line test".
  3. Remove the DSL cable from the FRITZ!Box.
  4. Click the "Calibrate" button and click "OK" to start the calibration.
  5. Reconnect the DSL cable to the FRITZ!Box once calibration is completed.
  6. Click the "Measure" button and click "OK" to start the DSL line test.
  7. Work through the instructions in the section matching your result.

Line test reports: DSL cable defective or not inserted

  1. Use a different DSL cable (for instance, from another DSL modem) to connect the FRITZ!Box to the DSL line.
    • If you are still using the FRITZ!Box on a DSL line with a conventional analog or ISDN landline:
      1. Remove the DSL/telephone cable from the DSL port of the splitter and from the FRITZ!Box.
      2. Pick up the red or yellow network cable included with delivery.
      3. Insert one end of the cable into the "DSL/Tel" port on the FRITZ!Box, and the other into the socket on the DSL splitter labeled "DSL".
  2. If the Power LED lights up constantly for 10 minutes, the DSL cable used before is defective. You can either purchase a new cable from an electronics retailer, or order it by mail to zubehoer@avm.de.
    • Note:You can also make a suitable new cable yourself. This guide contains information on the pin assignment.

Line test reports: Error in on-site wiring

  1. Remove the DSL splitter if you are using the FRITZ!Box on an IP-based connection.
  2. Remove all cable extensions, unused cables, telephone jacks, and additional electrical components (for example surge protection, automatic extension outlets).
  3. Make sure that the FRITZ!Box is correctly connected to your DSL line. You will find detailed instructions on the installation poster included with the FRITZ!Box and in the manual.

Line test reports: Error with provider

  1. Either: Test whether a different DSL modem works on your DSL line.
    • Or: Test whether the FRITZ!Box can establish a DSL connection on a different DSL line, for example at your neighbor's.

      Note:Only connect the FRITZ!Box to the DSL line and the power mains. A DSL connection was established if the "Power" LED remains lit after no more than 10 minutes.

  2. If another modem also does not work on your line, or if your FRITZ!Box can establish a DSL connection on a different line, then there is a problem with your DSL line. Contact your DSL provider and have them check your DSL line.

    ATTENTION!You may be charged for checking. Ask your provider about charges in advance!

7 Using a different DSL version

The DSL version of the FRITZ!Box undergoes constant development with each FRITZ!OS to ensure that it can establish optimal DSL connections under all circumstances. In individual cases (for example on DSL lines with outdated DSLAMs) the FRITZ!Box may only be able to establish a DSL connection with certain DSL versions. Therefore, test the current and the previous DSL version:

Using the latest FRITZ!OS

The DSL version is part of FRITZ!OS. Make sure that the FRITZ!Box is using the latest FRITZ!OS and therefore the latest DSL version:

Using the previous DSL version

If the problem occurs with the latest DSL version (for example after updating FRITZ!OS), test the DSL version of the previous FRITZ!OS:

  1. Click "Internet" in the FRITZ!Box user interface.
  2. Click "DSL Information" in the "Internet" menu.
  3. Click on the "Line Settings" tab. If the tab is not displayed, enable the Advanced View first.
  4. Enable the option "Use previous DSL version".
  5. Click "Apply" to save the settings.

Now the previous DSL version is enabled and the FRITZ!Box is restarted. The restart will take about two minutes.