STR-DN840 - Sony Audio Service Manual (repair manual). Page 5

NOTE  OF  REPLACING  THE  Q550,  Q551,  Q600,   
Q601,  Q650,  Q651,  Q700,  Q701,  Q750,  Q751,  Q800,  
Q801,  Q850  AND  Q851  ON  THE  MAIN  BOARD
Replacement of Q550, Q551, Q600, Q601, Q650, Q651, Q700, 
Q701, Q750, Q751, Q800, Q801, Q850 AND Q851 on the MAIN 
board used in this unit requires L type screw driver.

US, Canadian

4-454-452-0[]

AEP, UK

4-454-452-1[]

Australian

4-454-452-2[]

Taiwan

4-454-452-3[]

Mexican

4-454-452-4[]

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  REPLACING  THE  IC3506  ON  THE  DIGITAL  
BOARD
IC3506 on the DIGITAL board cannot exchange with single. 
When this part on the DIGITAL board is damaged, exchange the 
entire mounted board.

NOTE  OF  REPLACING  THE  IC901  ON  THE  STANDBY 
BOARD
IC901 on the STANDBY board cannot exchange with single. 
When this part on the STANDBY board is damaged, exchange the 
entire mounted board.

Note: Refer to Supplement-1 for adding SERVICING NOTES 

(TROUBLESHOOTING).