XM-S400D - Sony Car 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.

CONFIRMING  THE  OPERATION
Please confi rm the car audio unit works even if REM output is not 
connected when you connect this unit with the car audio unit by 
the HIGH LEVEL input.

Thermal Protect
TH503 TEMP_POW2
1.  Short across TH503 with the power on in normal room envi-

ronment.

2.  Verify that the protector is operated and POWER/PROTECT 

indicator fl ashes quickly (once every 0.2 seconds). When input 
the signal and verify that there is no output on the SP-OUT.

 

However in normal operation this condition will occur if tem-
perature of TH503 is about 120 ± 5 °C.

3.  Verify that the protector is released and there is an output on 

the SP-OUT when the short was removed and reset the AMP 
REM.

TH502 TEMP and TH501 TEMP_AMP
1.  Input signal then short across TH501 with the power on in nor-

mal room environment.

2.  Verify that the protector is operated and the POWER/PRO-

TECT indicator fl ashes slowly (once every second) then verify 
that output signal on the SP-OUT reduce.

 

However in normal operation this condition will occur if tem-
perature of TH501 is about 101 ± 4 °C and temperature of 
TH501 and TH502 difference more than 45 ± 2 °C.

3.  Verify that the protector is released and output signal on the 

SP-OUT is increate when the short was removed.

Remark:
IC301 there are Over Current Protection, Offset Protection and 
Thermal Protection function.
So it also can protect these ones by itself.

DESTINATION  ABBREVIATIONS
The following abbreviations for model destinations are used in this 
service manual.

• Abbreviations
  U 

: US, Canadian, AEP, UK, E, Australian models

  IND 

: Indian model

NOTE  FOR  REPAIRING  BOARD
Only part of electrical parts that mounted on the board of this unit 
can be replaced for repair.
Refer to “6. ELECTRICAL PARTS LIST” about electrical parts 
for service.
Since electrical parts that are not described in the electrical parts 
list cannot be replaced for repair, replace the complete mounted 
board when these electrical parts are defective.

GREASE  APPLYING  OF REPLACING  THE  COMPLETE  
MAIN  BOARD  OR  IC301  ON  THE  MAIN  BOARD
When the complete MAIN board or IC301 on the MAIN board are 
replaced, be sure to apply the grease (OIL COMPOUND (KS609)) 
so as to cover the IC301 on the MAIN board.