That would probably mean its broken yes..i have had them and just got my xbox back today after a month of waiting for it..you will probably be in for a month without xbox as well have fun.
The only time I've seen all red lights is when you turn it on without the AV cord plugged in. And I think the extended 3-year warranty only covers the 3 flashing lights so that wouldn't help you. I may be wrong though.