3
ZS-YN7
SECTION 1
SERVICING NOTES
The laser diode in the optical pick-up block may suffer electrostatic
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 flexible 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 reflective surface by the objective lens in the optical pick-
up block. Therefore, when checking the laser diode emission,
observe from more than 30 cm away from the objective lens.
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)
: LEAD FREE MARK
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 viscou-s (sticky, less prone to flow)
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.
NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
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 S421. (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 S421 as shown in Fig.1.
Note:
Do not push the detection lever strongly, or it may be bent or damaged.
3. Press the
u
button.
4. Check the object lens for confirming 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.
Fig.1 Method to push the S421
2
1
S421
