Sony SA-WCT770, Service Manual

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SA-WCT770
4
SECTION 1
SERVICING NOTES
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)
: LEAD FREE MARK
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-WCT770/SA-
CT770) are required to con
fi rming operation of SA-WCT770.
Check in advance 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.
“PRTECT (PROTECT)” APPEARS ON THE DISPLAY OF
THE BAR SPEAKER (SA-CT770)
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 IC104 ON THE SUB MAIN
BOARD AND THE COMPLETE SUB MAIN BOARD
When IC104 on the SUB MAIN board and the complete SUB
MAIN board are replaced, it is necessary to spread the compound
between the SUB MAIN board and the heat sink.
Spread the compound (THERMAL COMPOUND (G747)) refer-
ring to the
fi gure below.
– SUB MAIN Board (Side A) –
IC104
thermal compound (G747)
CAPACITOR ELECTRICAL DISCHARGE PROCESSING
When checking the board, for the electric shock prevention, con-
nect the resistors to both ends of respective capacitor (C935 or
C936) to discharge the capacitor (C935 or C936).
– POWER Board (Conductor Side) –
800
:
/2 W
C935 (US, Canadian and Taiwan models)
C936 (Except US, Canadian and Taiwan models)
Ver. 1.1