FRITZ!Box 7390 – Service - Knowledge Base

FRITZ!Box 7390 – Service

Occasional restarts: Several LEDs flash

The FRITZ!Box occasionally restarts (reboots, resets). When this happens, all or several LEDs either flash briefly several times or continuously one after another. The interval between restarts varies (for example a few times a week, several times a day, when specific events or actions occur), but restarts do not occur constantly.

Important:If the FRITZ!Box constantly restarts, follow the instructions in this guide.

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

1 Installing the latest FRITZ!OS

2 Using the correct power supply unit

One of the most frequent causes is the use of an unsuitable power supply unit for the FRITZ!Box. For example, you may be using the power supply unit from a different FRITZ!Box model:

3 Checking the cabling

If you are using the FRITZ!Box on an IP-based line without a conventional analog or ISDN landline, do not plug in the end of the Y-shaped cable for landline. Otherwise, interference is transmitted to the FRITZ!Box:

  • Check whether the black end of the Y-shaped cable is plugged in somewhere. If so, unplug the cable.

4 Disconnecting USB devices for testing purposes

Interference from USB devices connected to the FRITZ!Box may be causing the error. If this is the case, the USB devices may be defective, or the devices' system memory or file system may be damaged. USB devices that require more than 500 mA of current, for example 2.5 inch hard drives or UMTS sticks, can also cause disturbances.
In order to test whether a USB device is causing the issue, proceed step by step as follows:

  1. Remove all USB devices from the FRITZ!Box.
  2. For a sufficient period of time, observe whether the issue reoccurs.
  3. Connect the other USB devices one by one; only connect one USB device at a time.
  4. Check which USB device causes the issue to occur again.
  5. Connect this USB device to the FRITZ!Box by means of a USB hub with its own power supply for testing purposes.

    According to the USB specifications, the power consumption of a USB device may not exceed 500 mA. If the device requires more than this, it must be connected to the FRITZ!Box by means of a USB hub with its own power supply (active USB hub).

  6. For testing purposes, replace this device if the issue also occurs when using it with an active hub.

5 Configuring file sharing software

The following steps are only necessary if you are using file sharing software (such as eMule, BitTorrent):

  • In the file sharing software, decrease the number of simultaneous connections that are allowed.

6 Loading the FRITZ!Box factory settings for testing purposes

In order to test whether the issue occurs because the FRITZ!Box was incorrectly configured, first save the settings of your FRITZ!Box and then load the FRITZ!Box's factory settings for testing purposes:

  1. Save the FRITZ!Box settings.
  2. Use the user interface to load the FRITZ!Box's factory settings.
  3. Reconfigure your FRITZ!Box. For this test, you only need to configure the basic functions of the FRITZ!Box.
  4. For a sufficient period of time, test whether the problem still occurs.
    • If the issue no longer occurs, then the previous settings were incorrect:
      • Completely reconfigure your FRITZ!Box.
    • If the issue persists:
      1. Restore all of the FRITZ!Box settings.
      2. Proceed with the following section.

7 Resetting the FRITZ!Box

8 Enabling the automatic sending of error reports

You can configure your FRITZ!Box to automatically send error reports. Automatic error reports do not contain any personal information such as passwords or Internet account information. The data we receive can help to eliminate the occurrence of sudden restarts in a future FRITZ!OS update, if the cause is reproducible and one we can eliminate.

  1. Open the FRITZ!Box user interface.
  2. Click on "Contents" on the bottom of the page.
  3. Click on "AVM Services" at the very bottom of the next window.
  4. Enable the option "Diagnostics and Maintenance" ("Diagnose und Wartung").
  5. If you enter an e-mail address, it can be used for any queries that might arise during the processing of the report.
  6. Click "OK" to save the settings.