HT-CT770 - 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.

ADVANCE  PREPARATION  WHEN  CONFIRMING  OP-
ERATION
All of the units included in the HT-CT770 (SA-CT770/SA-WCT770) 
are required to confi rming operation of SA-CT770. Check in ad-
vance that you have all of the units.

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  PARTS  ON  THE  HDMI  BOARD
In Except US and Canadian models of this unit, each parts for Ref. 
No. CN3000/3001/3002/3006 and Ref. No. RB3000/3001 is using 
two kinds of parts.
When replacing these parts, it is necessary to replace it for parts 
same as parts before replacing, and there is a combination.
Replace the parts after distinguishing the type of parts referring to 
the following.

Distinguishing 
Method

CN3000/3001/
3002/3006

Part No.
1-843-486-21

Part No.
1-821-398-41

RB3000/3001

Part No.
1-457-539-11

Part No.
1-234-400-21

NOTE  OF  REPLACING  THE  IC3009  ON  THE  HDMI 
BOARD
IC3009 on the HDMI board cannot replace with single. When this 
part is damaged, replace the complete mounted board.

NOTE  OF  REPLACING  THE  IC1009,  IC1010  AND  IC1012  
ON  THE  MAIN  BOARD
IC1009, IC1010 and IC1012 on the MAIN board cannot replace 
with single. When these parts are damaged, replace the complete 
mounted board.

q Press the ÒÄÆ (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.

NOTE  OF  REPLACING  THE  IC3001  ON  THE  MAIN  
BOARD  AND  THE  COMPLETE  MAIN  BOARD
When IC3001 on the MAIN board and the complete MAIN board 
are replaced, it is necessary to spread the compound between the 
MAIN board and the heat sink.
Spread the compound (THERMAL COMPOUND (G747)) refer-
ring to the fi gure below.

CAPACITOR  ELECTRICAL  DISCHARGE  PROCESSING 
When checking the board, for the electric shock prevention, con-
nect the resistors to both ends of respective capacitor (C914 or 
C915) to discharge the capacitor (C914 or C915).

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