To the knowledge base

Occasional restarts: Several LEDs flash

The FRITZ!Box restarts occasionally. When this happens, all or several LEDs flash continuously. It restarts a few times a week, several times a day, or when specific events or actions occur, for example, but not constantly.

Important:If the FRITZ!Box restarts constantly, proceed as described in in this guide.

Note:All instructions on configuration and settings given in this guide refer to the latest FRITZ!OS for the FRITZ!Box.

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

1 Installing the latest FRITZ!OS

  1. Install the latest FRITZ!OS on the FRITZ!Box.

2 Using the correct power adapter

Using an unsuitable power adapter for the FRITZ!Box is one of the most common causes of error:

  1. Use a suitable power adapter to plug in your FRITZ!Box.

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:

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

4 Testing whether a USB device is interfering

The problem may be caused by a USB device connected to the FRITZ!Box:

  1. Remove all USB devices from the FRITZ!Box. If the problem no longer occurs then, either a USB device or its cable is faulty, or a device consumes too much power.
  2. Reconnect the USB devices to the FRITZ!Box one by one to find out which device causes the problem.
  3. For testing purposes, use a USB hub with its own power supply (active USB hub) to connect the device causing interference to the FRITZ!Box.
  4. If the problem also occurs when using it with an active hub, replace the USB device.

5 Configuring file sharing software

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

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

6 Checking the FRITZ!Box and settings

Loading the factory settings

  1. Load the FRITZ!Box's factory settings.

Checking the settings

  1. Reconfigure the basic functions of the FRITZ!Box.
  2. Check whether the problem still occurs.
  3. If the problem no longer occurs, completely reconfigure the FRITZ!Box. The FRITZ!Box's settings were incorrect.
    • If the problem still occurs, use the recovery program to reset the FRITZ!Box. The FRITZ!Box is in an error state.

If it still keeps restarting, this is due to a safeguard mechanism that protects the FRITZ!Box from errors caused by overload, for example. The automatic restart restores the FRITZ!Box to working order.