I bought from ebay last week, at a very cheap price, a Fritz 7170 (avm 04047 Edition F) that was sold as damaged: the seller said the power went off during a firmware update, and now when I connect it there is absolutely no leds at all, no signals of the fritz turning on. is it completely damaged? is it a burnt component? I tried a different power supply but same result. or the main boot loader is damaged and I can fix it with jtag?