D-NF430/NF431
SECTION 1
SERVICING NOTES
NOTES ON HANDLING THE OPTICAL PICK-UPLASER DIODE AND FOCUS SEARCH OPERATION
BLOCK OR BASE UNITCHECK
During normal operation of the equipment, emission of the laser
The laser diode in the optical pick-up block may sufdiode is prohibited unless the upper lid is closed while turning onfer electrostatic
break-down because of the potential difference generated by thethe S801. (push switch type)
charged electrostatic load, etc. on clothing and the human bodThe following checking method for the laser diode is opery.able.
During repair, pay attention to electrostatic break-down and also
use the procedure in the printed matter which is included in theY Method:
repair parts.Emission of the laser diode is visually checked.
The flexible board is easily damaged and should be handled with1. Open the upper lid.
care.2. With a disc not set, turn on the S801 with a screwdriver having
a thin tip as shown in Fig.1.
NOTES ON LASER DIODE EMISSION CHECK3. Press theu button.
The laser beam on this model is concentrated so as to be focused on4. Observing the objective lens, check that the laser diode emits
the disc reflective surface by the objective lens in the optical pick-light.
up block. Therefore, when checking the laser diode emission,When the laser diode does not emit light, automatic power
observe from more than 30 cm away from the objective lens.control circuit or optical pick-up is faulty.
In this operation, the objective lens will move up and down 2
UNLEADED SOLDERtimes along with inward motion for the focus search.
Boards requiring use of unleaded solder are printed with the lead-
free mark (LF) indicating the solder contains no lead.lever (detector)
(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 iflever (detector)
the heated tip is applied for too long, so be careful!
? Strong viscosity
Unleaded solder is more viscou-s (sticky, less prone to flow)S801
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.
OPERATION CHECK WHEN THE LID IS OPENMAIN board
In performing the repair with the power supplied to the set, removing
the MAIN board causes the set to be disabled.Fig. 1 Method to push the S801
In such a case, make a solder bridge to short SL805 (OPEN) on the
MAIN board in advance.
NOTE ON REPLACEMENT OF MAIN BOARD OR
� MAIN Board (Component Side) �EEPROM (IC802)
When MAIN board is replaced or EEPROM (IC802) on the MAIN
board is replaced, patch processing is needed.
Confirm about information of patch processing to each service
headquarters.
SL805
(OPEN)
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ACEC
