you cant reach the router.
the avalon is still there, conect it to your PC with cgminer installed via USB, asap, then you think about repairing/reseting the router.
Thanks for that quick answer! I have to install cgminer first on my Laptop...
Can the router be reset by the small button? How? What IP does it have afterwards? Will I be able to flash it again with the latest custom firmware?
Really appreciate your help.