==============================================================================
                             K E N W O O D
   >>>   A M A T E U R   R A D I O   S E R V I C E   B U L L E T I N   <<<
==============================================================================

                        Kenwood Service Centers

   Kenwood Service Corporation             Kenwood Service Center, East
   2201 East Dominguez Street              829 Lynnhaven Parkway, Suite 130
   Long Beach, California 90801            Virginia Beach, Virginia 23452
   Telephone 1-310-639-5300                Telephone 1-804-340-1702

==============================================================================

BULLETIN # 989
MODEL: DRU-2
SUBJECT: Erratic Playback/Memory Loss

Erratic operation of the DRU-2 such as loss of recorded data, or erratic 
message playback might be caused by premature backup battery failure. 
This premature failure is due to an excessive current drain that is placed 
on the DRU-2 battery (over 100 uA) when connected to the TS-850S. No backup 
current is drawn when the DRU-2 is not installed, so shelf life of new units 
should not be affected. The following procedure will correct this syrnptom.

Parts requirted: 

Modification parts kit W05-0379-00 (Consists of the following items)

Insulator (top) F20-0520-04 
Lithium battery W09-0326-05
DTC-124ES transistor DTC-124ES 
Insulator (bottom) F20-0521-04
2.2 uF 25v tantalum cap. CSl5ElE2RM 
Insulating tubing

Procedure

1. Add a DTC-124ES transistor and 2.2 uF tantalum capacitor to the ACL line of 
   the DRU-2 unit as shown. 

2. Change R21 from a 10 K ohm resistor to a 560 ohm resistor. (Note: Piggy 
   back the 560 ohm resistor on top of the 10 K ohm resistor if you do not 
   have the proper soldering equipment to remove chip resistors.) 

3. Cut the ACL line at connector W3.
                     

  To ACL On W3  <--c-----\  b
                          |-----2.2 uF---->5v
    To Ground   <--e-----/     -      +

                       DTC-124ES


These modifications are performed on the foil side of the PC Borad.

Time required for this procedure is 30 minutes or less.