I found that when I patched the drive from 812s to 832s using the EEProm_Utility.exe provided from Codeguys, the drive won't recognize if there's a cdr or dvd+rw disc inserted. If I upgrade the firmware from US0Q to US0S using official upgrade exe, the drive won't see any disc inserted again. If I now patched again using Codeguys' EEProm_Utility.exe for 812s to 832s, the condition has no changed. If I roll back from 832s to 812s using Codeguys' utility, the condition is the same. But if I finally restore the original firmware using official US0Q, the drive can read disc normally.
It shows that Codeguys' EEProm_Utility.exe is not working for upgrading 812s to 832s or restoring .bin file. The latest official firmware US0S doesn't work too.
What so weird dvdrw drive! Does it tell that the drive is faulty? Thx for any suggestion.