I had openwrt running with luci on my AVM Fritzbox 4040. So when I started to set it up, i setup some interfaces and firewalls. Now i found a new tutorial to set up more stuff openwrt is used to be known and makes it a great firmware.
I set the lan interface to static ip.
But here comes the thing:
I set my lan to a new IP and pressed enter.
Of course from now I couldnt reach it of the webbrowser again an after the counter ran down it asked me to save the the new settings.
So i started to log on with the new ip, but i doesnt work.
I tried with failsafe (what i can see with the blink7ng code). But i cant access by ssh.
I downloaded the AVM recovering tool and its also not working. When i set up the pc with some other network settings it had found it, but it says it has some other software issues and stops.
What can I do from now. I dont know how to do next step. Anybody knows.
To be clear, the reset procedure offered by @ZebraOnPC does not apply to OpenWrt -- it may apply to some vendor's factory firmware, though.
In the case of the Fritzbox running it's vendor firmware, theoretically there is a "forgot password" option that will allow you to factory reset the device. There is some additional info here and here.
If you're running OpenWrt, typically the WPS button can be used to enter failsafe... apply power an then repeatedly press the button until you see a rapidly flashing LED (I don't know which one, but it should be obvious). If that doesn't work, there appears to be another button ("wifi") on the 4040, so try that one. From there, you can follow the link that @lleachii provided earlier.