Sony Tc Kb820s Manual

MICROFILM
SERVICE MANUAL
STEREO CASSETTE DECK
AEP Model
UK Model
Australian Model
Model Name Using Similar Mechanism TC-KE400S
Tape Transport Mechanism Type TCM-190VB12CSS
SPECIFICATIONS
TC-KB820S
Dolby noise reduction and HX Pro headroom ex-
tension manufactured under license from Dolby
Laboratories Licensing Corporation. HX Pro origi-
nated by Bang & Olufsen.
ÒDOLBYÓ, the double-D symbol a, and ÒHX PROÓ
are trademarks of Dolby Laboratories Licensing Cor-
poration.
Ð Continued on next page Ð 

Ð 2 Ð
Flexible Circuit Board Repairing
¥ Keep the temperature of the soldering iron around 270 ûC dur-
ing repairing.
¥ Do not touch the soldering iron on the same conductor of the
circuit board (within 3 times).
¥ Be careful not to apply force on the conductor when soldering
or unsoldering.
Notes on chip component replacement
¥ Never reuse a disconnected chip component.
¥ Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.
SAFETY-RELATED  COMPONENT  WARNING!!
COMPONENTS...

Ð 3 Ð
TABLE  OF  CONTENTS
1. GENERAL
................................................................... 4
2. DISASSEMBLY......................................................... 5
3. MECHANICAL  ADJUSTMENTS....................... 9
4. ELECTRICAL  ADJUSTMENTS......................... 10
5. DIAGRAMS
5-1. Note for Printed Wiring Boards and
Schematic Diagrams ....................................................... 14
5-2. Printed Wiring Boards  Ð MD Section Ð ......................... 15
5-3. Schematic...

Ð 4 Ð
SECTION  1
GENERAL
LOCATION OF CONTROLS
1I/O (Power) button
2Remote control sensor
3PHONES jack
4Display panel
5Tape operation buttons
AMS* 0 button
á button
AMS* ) button
p button
P PAUSE button
R REC MUTING button
r REC button
6Tape counter
7Counter buttons
RESET button
MEMORY button8Cassette holder
9¤ EJECT button
!¼AUTO CAL button
!ÁDOLBY NR switch
!ªBALANCE control
!£REC LEVEL control
*  AMS is an abbreviation for Automatic Music Sensor. 

Ð 5 Ð
FRONT  PANEL  SECTION
MD  ASSÕY  SECTION
Note: Follow the disassembly procedure in the numerical order given.
SECTION  2
DISASSEMBLY
CASE
Unscrew the four case attachment seven tapping screws
and remove the case.
1flat cable
(CN801)
3screw
(BVTP3 ´ 8)
5four screws
(BVTP3 ´ 8)
7two connectors
(CNP31, 33)
5screw
(BVTP3 ´ 8)
6claw
6claw
1flat cable(CN504)
4two earth
lugs
2connector
(CN704)
1flat cable
(CN81)
2connector
(CN506)
8front panel section
4two screws
(BVTT2.6 ´ 8)
6Remove the MD ass’y...

Ð 6 Ð
MAIN  BOARD
CASSETTE  HOLDER  (R)  ASSÕY
4two screws
(BVTP3 ´ 8)
2screw
(BV/ring)
5MAIN board
1connector
(CN701)
4screw
(BV/ring)
3bracket (TR)
2boss
3shaft
1torsion spring
4cassette holder (R)
ass’y 

Ð 7 Ð
FITTING  BASE  BLOCK
HEAD
2two screws
(PTPWH2 ´ 23)
2screw
(PTPWH2 ´ 23)
Note: When installing, pull
the FR belt and put 
around the claws as 
shown below.
1connector
(CNP32)
3fitting base block
Note: When installing, pull the capstan belt 
and put around the claws as shown below.
2screw
(B2 ´ 10)
1connector(CNP32)
4azimuth screw
5record/playback head6compression spring
3erase head 

Ð 8 Ð
MOTOR
5two screws
(B2.6 ´ 3)
7two screws
(P2.6 ´ 2.8)
2flexible board
(CNP72)
1connector
(CNP71)
3claw
3claw
3two 
claws
6capstan motor
!¼ground plate
4audio
board
8reel motor
9FR belt 

Ð 9 Ð
SECTION  3
MECHANICAL  ADJUSTMENTS
PRECAUTION
1. Clean the following parts with a denatured alcohol-moistened
swab:
record/playback/erase head pinch roller
rubber belts capstan
idler
2. Demagnetize the record/playback head with a head demagne-
tizer.
(Head demagnetizer do not approach for the erase head.)
3. Do not use a magnetized screwdriver for the adjustment.
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
5. The adjustments should be performed with the rated...

Ð 10 Ð
SECTION  4
ELECTRICAL  ADJUSTMENTS
Note:The adjustment should be performed in the order given in the ser-
vice manual. As a rule, adjustments about playback should be per-
formed before those about recording.
The adjustments should be performed before for both L-CH and R-
CH.
¥ Switches and controls should be set as follows unless otherwise
specified.
DOLBY NR, MPX FILTER switch : OFF
¥ Standard Record:
Deliver the standard input signal level to the input jack and set
the REC LEVEL control to...