SA-MS5500, SA-WMS55, SS-CNMS55, SS-FMS55, SS-SRMS55 - Sony Audio Service Manual (repair manual). Page 2

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  THE  PARTS  ON  THE  EACH  BOARDS  REPAIR-
ING (SA-WMS55)
When the IC7 on the MAIN board is damaged, exchange this part.
When the mount parts other than IC7 on the MAIN board are 
damaged, exchange the ASSY parts including complete mounted 
board.
Printed wiring board and schematic diagram have been described 
to this service manual is for the reference.
Refer to EXPLODED VIEWS (page 8) for part No. of the IC7.

NOTE  THE  IC7  ON  THE  MAIN  BOARD  REPLACING 
(SA-WMS55)
When the IC7 on the MAIN board is replaced, it is necessary to 
spread grease between the IC7 and INSULATION SHEET and be-
tween the heat sink and INSULATION SHEET.
Spread grease referring to the fi gure below.

Part No. 

Description

7-651-000-50  GREASE, SILICON (G-746) 200G