WX-GT77UI, WX-GT78UI, WX-GT78UIM - Sony Car Audio Service Manual (repair manual). Page 3

CD-DA

MP3

WMA

AAC

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.

 •  CD Play back

This unit can play CD-DA (also containing CD TEXT) and 
CD-R/CD-RW (MP3/WMA/AAC fi les).

This compact disc player is classifi ed as a CLASS 1 LASER      
product. The CLASS 1 LASER PRODUCT label is located on the 
exterior.

This label is located on the bottom of the chassis.

 ...................................................   4

 

Location of Controls .......................................................   5

 Connections 

....................................................................  

6

3-1.   Front Panel Assy  ............................................................   7
3-2.   Sub Panel Assy  ...............................................................   8
3-3.   CD Mechanism Block .....................................................   8
3-4.   Main Board .....................................................................   9
3-5. Servo 

Board 

....................................................................   9

3-6.  Chassis (T) Sub Assy ......................................................   10
3-7.  Roller Arm Assy ..............................................................   10
3-8. Chassis 

(OP) 

Assy 

...........................................................  11

3-9.  Chucking Arm Sub Assy .................................................   11
3-10. Sled Motor Assy ..............................................................   12
3-11.  Optical Pick-up Section ..................................................   13
3-12. Optical Pick-up ...............................................................   13

4-1.  Block Diagram –Main Section– .....................................   15
4-2.  Block Diagram –Display Section– .................................   16
4-3.  Printed Wiring Board –Main Section– ............................   18
4-4.  Schematic Diagram –Main Section (1/3)– ......................   19
4-5.  Schematic Diagram –Main Section (2/3)– ......................   20
4-6.  Schematic Diagram –Main Section (3/3)– ......................   21
4-7.  Printed Wiring Board –Sub Section– ..............................   22
4-8.  Schematic Diagram –Sub Section– .................................   23
4-9.  Printed Wiring Board –Key Section (1/2)– .....................   24
4-10.  Printed Wiring Board –Key Section (2/2)– .....................   25
4-11.  Schematic Diagram –Key Section– ................................   26

5-1. Sub 

Panel 

Section 

...........................................................  33

5-2.  Front Panel Section .........................................................   34
5-3.  Main Board Section ........................................................   35
5-4.  CD Mechanism Section (MG-101Z-188//Q) ..................   36

  ..............................   37