SA-WGT5D - 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.

The laser diode in the optical pick-up block may suffer electro-
static break-down because of the potential difference generated by 
the charged electrostatic load, etc. on clothing and the human body.
During repair, pay attention to electrostatic break-down and also 
use the procedure in the printed matter which is included in the 
repair parts.
The fl exible board is easily damaged and should be handled with 
care.

NOTES  ON  LASER  DIODE  EMISSION  CHECK
The laser beam on this model is concentrated so as to be focused 
on the disc refl ective surface by the objective lens in the optical 
pickup block. Therefore, when checking the laser diode emission, 
observe from more than 30 cm away from the objective lens.

NOTE  OF  PERFORMING  THE  OPERATION  CHECK
When performing the operation check of this unit, be sure to per-
form the operation check in the state that heat sink is installed. If  
operating in the state that heat sink is not installed, it is possibility 
that become the protect state.

CAPACITOR  ELECTRICAL  DISCHARGE  PROCESSING 
When checking the board, for the electric shock prevention, con-
nect the resistors to respective parts to discharge.
When discharging the capacitor (Ref. No. C27) on the switching 
regulator (SSN-152AD) (Ref. No. SWR1), it can discharge the 
whole unit.

Discharge method 1:
Connect the resistors to both ends of capacitor (Ref. No. C27) on the 
switching regulator (SSN-152AD) (Ref. No. SWR1) to discharge.

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Discharge method 2:
When connecting the resistor to both ends of capacitor (Ref. No. 
C27) on the switching regulator (SSN-152AD) (Ref. No. SWR1) 
is diffi cult, discharge by connecting the resistor between fuse (Ref. 
No. F4) and jumper (Ref. No. J26 or J74).

Note: Be careful not to short-circuit, because between the terminal is close.

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If having removed the wire from connector (Ref. No, CN2001) on 
the D-AMP board before discharging by the switching regulator 
(SSN-152AD) (Ref. No. SWR1), discharge by connecting the re-
sistor between pin 1, 2, 3 (+VH) and pin 7, 8, 9 (–VH) of connector 
(Ref. No, CN2001) on the D-AMP board.

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