Servicing Notes - Sony HCD-EP303 Service Manual

HCD-EP303
NOTES ON HANDLING THE OPTICAL PICK-UP
BLOCK OR BASE UNIT
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.
LASER DIODE AND FOCUS SEARCH OPERATION
CHECK
1. Press the ?/1 button to the power ON with no disc inserted
and press the CD button.
2. Open the lid for CD.
3. Turn on SW600 as following figure.
4. Confirm the laser diode emission while observing the objecting
lens. When there is no emission, Auto Power Control circuit or
Optical Pick-up is broken.
Objective lens moves up and down five times for the focus
search.
4
SECTION 1

SERVICING NOTES

• MODEL IDENTIFICATION
– Bottom View –
AEP, UK models
EXCEPT AEP, UK models
TO PREVENT 'TAPE OSCILLATION SOUND AT VOLUME'
MAXIMUM SETTING (W/O TAPE)
Headphone wire dressing:
a.) Draw the wire from Main board to Headphone board along the
b.) The wire must be kept away from the top side of Cassette board
SW600
PART No.
MODEL
bottom side of heatsink.
at least 30 mm.
MAIN board
HEADPHONE
board
at least 30 mm
PART No.
4-235-972-0
<
4-241-498-0
<
heatsink
CASSETTE board