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D-NE319/NE320/NE321/NE321CK/NE326CK
SECTION 1
SERVICING NOTES
The laser diode in the optical pick-up block may suffer electrostatic
breakdown because of the potential difference generated by the
charged electrostatic load, etc. on clothing and the human body.
During repair, pay attention to electrostatic breakdown 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.
NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
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.
OPERATION CHECK WHEN THE LID IS OPEN
In performing the repair with the power supplied to the set, removing
the JACK board causes the set to be disabled.
In such a case, make a solder bridge to short SL501 (OPEN) on the
JA CK board in advance.
-“ JACK Board (Component Side) -“
SL501
(OPEN)
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 S502. (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. With a disc not set, turn on the S502 with a screwdriver having a thin tip as shown in Fig. 1.
3. Push the u ENTER button.
4. Observing the objective lens, check that the laser diode emits light.
When the laser diode does not emit light, automatic power control circuit or optical pick-up is faulty.
In this operation, the objective lens will move up and down 2 times along with inward motion for the focus search.
NOTES ON REPLACEMENT OF EGL BOARD OR
EEPROM (IC1602)
When EGL board is replaced or EEPROM (IC1602) on the EGL
board is replaced, patch processing is needed.
Confirm about information of patch processing to each service
headquarters.
Fig. 1 Method to push the S502
S502 lever (detection)
lever (detection) JACK board
Ver. 1.7
