ZS-RS70BT, ZS-RS70BTB - 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.

NOTE  OF  REPLACING  THE  IC801  ON  THE  MAIN BOARD
IC801 on the MAIN board cannot replace with single. When this 
part is damaged, replace the complete mounted board.

TEST  DISCS
Use following TEST DISC (for CD) when this unit confi rms the 
operation and checks it.

Part No.

   

Description

3-702-101-01 DISC 

(YEDS-18), 

TEST

4-225-203-01 DISC 

(PATD-012), 

TEST

CHUCK  PLATE  JIG  ON  REPAIRING
On repairing CD section, playing a disc without the CD lid, use 
CHUCK PLATE JIG.

Note: The optical pick-up block has been changed in the midway of produc-

tion. It is not necessary for the optical pick-up block after change to use 
the CHUCK PLATE JIG.

Part No.

   

Description

X-4918-255-1 

CHUCK PLATE JIG

NEW/FORMER  DISCRIMINATION  OF  OPTICAL  PICK-UP  
BLOCK  OR  CD  LID
The optical pick-up block has been changed in the midway of pro-
duction. In addition, the CD lid has also been changed along with 
that, and the chucking plate has been deleted.
When replacing the optical pick-up block or CD lid, be sure to 
open the CD lid and check the presence or absence of the chucking 
plate on the bottom side of CD lid, and replace those after distin-
guishing the new/former.

LASER  DIODE  AND  FOCUS  SEARCH  OPERATION  
CHECK
During normal operation of the equipment, emission of the laser 
diode is prohibited unless the upper lid is closed while turning on 
the S801 (push switch type).
The following checking method for the laser diode is operable.

• Method
  Emission of the laser diode is visually checked.
  1.  Open the CD lid.
  2.  Press the [POWER] (Except AEP, East European, Russian 

and UK models)/[OPERATE] (AEP, East European, Russian 
and UK models) button to turn the power on.

  3.  Press the [CD] button to select CD function.
  4.  Push the S801 as shown in Fig.1.

Note: Do not push the detection lever strongly, or it may be bent or 

damaged.

  5.  Check the object lens for confi rming normal emission of the 

laser diode. If not emitting, there is a trouble in the automatic 
power control circuit or the optical pick-up.

   

In this operation, the object lens will move up and down 4 
times along with inward motion for the focus search.

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.