HT-XT3 - Sony Audio Service Manual (repair manual). Page 4

UNLEADED  SOLDER
Boards requiring use of unleaded solder are printed with the lead-
free mark (LF) indicating the solder contains no lead.
(Caution:  Some printed circuit boards may not come printed with 

the lead free mark due to their particular size)

Unleaded solder has the following characteristics.
•  Unleaded solder melts at a temperature about 40 °C higher 

than ordinary solder.

 

Ordinary soldering irons can be used but the iron tip has to be 
applied to the solder joint for a slightly longer time.

 

Soldering irons using a temperature regulator should be set to 
about 350 °C.
Caution: The printed pattern (copper foil) may peel away if 

the heated tip is applied for too long, so be careful!

• Strong 

viscosity

 

Unleaded solder is more viscous (sticky, less prone to fl ow) 
than ordinary solder so use caution not to let solder bridges 
occur such as on IC pins, etc.

•  Usable with ordinary solder
 

It is best to use only unleaded solder but unleaded solder may 
also be added to ordinary solder.

NOTE  OF  PERFORMING  THE  OPERATION  CHECK  IN  
THE  STATE  THAT  HEAT  SINK  WAS  REMOVED
When performing the operation check in the state that this unit was 
disassembled, it is possible to perform the operation check in the 
state that heat sink was removed. But don’t perform the operation 
check in the long time, and perform the operation check in the 
volume state as low as possible.

NOTE  OF  REPLACING  THE  IC1600  ON  THE  TOUCH 
BOARD
IC1600 on the TOUCH board cannot replace with single. When 
this part is damaged, replace the complete mounted board.

NOTE  OF  REPLACING  THE  IC101,  IC102,  IC103,  
IC301,  IC302,  IC303,  IC410,  IC3004  AND  IC5010  ON  
THE  MB-1408  BOARD
IC101, IC102, IC103, IC301, IC302, IC303, IC410, IC3004 and 
IC5010 on the MB-1408 board cannot replace with single. When 
these parts are damaged, replace the complete mounted board.

NOTE  OF  REPLACING  THE  IC102  AND  IC103  ON  
THE  MB-1408  BOARD
Replacement of IC102 and IC103 on the MB-1408 board used in 
this unit requires a special tool.

“PRTECT  (PROTECT)”  APPEARS  ON  THE  DISPLAY  
OF  THE  BAR  SPEAKER
c  Press the }/1 (on/standby) button to turn off the system. After 

the indicator disappears, disconnect the AC power cord (mains 
lead) then check that nothing is blocking the ventilation holes of 
the system.

CAPACITOR  ELECTRICAL  DISCHARGE  PROCESSING 
When checking the board, for the electric shock prevention, con-
nect the resistors to both ends of respective capacitor (C201 and 
C207) to discharge the capacitor (C201 and C207).

:/2 W

:/2 W

NOTE  OF  REPLACING  THE  IC6001  AND  IC6004  ON  
THE  AMP  BOARD  AND  THE  COMPLETE  AMP  BOARD
When IC6001 and IC6004 on the AMP board and the complete 
AMP board are replaced, it is necessary to spread the compound 
between the AMP board and the heat sink.
Spread the compound (THERMAL COMPOUND (G747)) 
referring to the figure below.

BOND  FIXATION  OF  ELECTRIC  PARTS
When SWITCHING REGULATOR (3L405W) board or MB-
1408 board or AMP board is replaced or the following object parts 
are replaced, it is necessary to fi x parts to the boards by using a 
specifi ed bond without fail.

• Object boards
SWITCHING REGULATOR (3L405W) board 
Complete MB-1408 board 
Complete AMP board

SWITCHING 
REGULATOR 
(3L405W)

C101, C102, C103, C201, C207, C211, C402, 
L401, NR101, R208, T201

MB-1408

CN707

AMP

C6104, C6108, C6109, L6001, L6007, L6008

Part No.

   

Description

7-600-020-70 

ADHESIVE (SC608Z2) 180ML

1. SWITCHING REGULATOR (3L405W) board (page 5)
2. MB-1408 board (page 5)
3. AMP board (page 5)