CMT-EH15, HCD-EH15 - Sony Audio Service Manual (repair manual). Page 3

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.

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 SW750. (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 upper lid.
  2.  Push the SW750 as shown in Fig.1.

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

damaged.

  3.  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 2 

times along with inward motion for the focus search.

Canadian and Mexican 
models

AC 120 V, 60 Hz

AEP, Russian and UK 
models

AC 230 V, 50/60 Hz 

Australian model

AC 230 – 240 V, 50/60 Hz

Argentina and Thai 
models

AC 220 V, 50/60 Hz

Korean model

AC 220 V, 60 Hz

Taiwan model

AC 120 V, 50/60 Hz

Singapore, Chilean and 
Peruvian models

AC 110 – 120 or 220 – 240 V, 
50/60 Hz

Brazilian model

AC 127 or 220 V, 50/60 Hz