im trying to download v. 4.77 update into my 987c si unit (i currently have v 3.17 i think") and have attempted the several options discussed to complete the update. I restored factory defaults turned the unit off then powered it back up then put the downloaded v4.77 SD card into the machine and the unit doesn't recognize the card? I have also tried powering down and installing the chip and still no success, Anybody had this problem?