It came back in 10 days. I sent it in due to falsing on Ka every few minutes; also some falsing on K.
bought it new in Sept 01. Was sent in one before for repairs back in March 06.
Here's what the customer repair report said was done:
"Replaced Antenna, recalibrated unit, updated software"
All this for $40. I have been very pleased with the 8500. Even though it is 7 years old, it still can hold its own.
I also have an X50 in another car.