Seems that Amazon recently has blocked downloading firmwares older than 5.8.5.
You can get 5.8.5, say for PW3, at
https://s3.amazonaws.com/firmwaredow...hite_5.8.5.bin
but cannot get 5.8.2 at
https://s3.amazonaws.com/firmwaredow...hite_5.8.2.bin
and older.
You can get 5.8.5, say for PW3, at
https://s3.amazonaws.com/firmwaredow...hite_5.8.5.bin
but cannot get 5.8.2 at
https://s3.amazonaws.com/firmwaredow...hite_5.8.2.bin
and older.