[Kenwood] TS 2000 serial number range

[John King via Kenwood]

Do any of you know the serial number range of TS 2000 transceivers that had factory defects or less than desirable characteristics in the filters and OR final transistors and or final amplifier boards in the Kenwood TS 2000 transceivers?
I just acquired one in the 803XXXXX serial number range. Haven't used it yet and would like to know more about the problematic serial number ranges before I use it. Please share your knowledge with me. Thanks and 73, John, K5PGW