Man, I've never had the 480s brick themselves, so that must have been some seriously loud shit Chris for you to overload the 480s. This is surely the recorder bricking.
FWIW, one thing I love about using the 480s with my R4 is the fact that the bodies not only have a 10db pad, but they also have a +7 db setting too. Combine that with the sensative R4 mic-ins, and you've got a lot of combos to work with:
1. Crazy Loud = -10pad running line-in R4
2. Loud = No pad running line-in R4
3. Somewhat Loud = +7 running line-in R4
4. Moderate = -10 pad running mic-in R4
5. Quiet = No pad running mic-in R4
6. Acoustic/Very Quiet = +7 running line-in R4