Servicing Note - Sony HCD-GR3 Service Manual

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.
HOW TO OPEN THE DISC TRAY WHEN POWER SWITCH
TURNS OFF
1 Remove the Case.
3 Pull-out the disc tray.
FL Display Tube, LED All Lit and Key Check mode
When the TUNER/BAND , DISPLAY , and MENU 2 buttons
are pressed simultaneously, the FL display tube and LEDs will all
light up. Press any button to enter the key check mode.
When the key check mode is entered, the FL display tube displays
"KEY 1 0 0". Each time a button is pressed, the counter increases
in the following order, KEY 2 n KEY 3 n KEY 4.
If buttons already pressed once are pressed again, the counter will
not increase. When the VOLUME knob is rotated in the + direc-
tion, the count increases in the following order.
0 0 n 0 1 n 0 2.
When rotated in the – direction, it decreases in the following order.
0 0 n 0 9 n 0 8.
To exit form the test mode, press the TUNER/BAND , DIS-
PLAY , MENU 2 buttons simultaneously again.
How to reset all
Pressing the TUNER/BAND , DISPLAY and MENU 3 but-
tons simultaneously, all are rest and returned to as when the was
shipped.
SECTION 1

SERVICING NOTE

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, ob-
serve from more than 30 cm away from the objective lens.
LASER DIODE AND FOCUS SEARCH OPERATION
CHECK
Carry out the "S curve check" in "CD section adjustment" and check
that the S curve waveform is output three times.
Switching the channel step 9 KHz/10 KHz
Press ENTER/NEXT button and POWER button simultaneously
to switch the AM channel step 9 KHz and 10 KHz. Be sure not to
change with carelessness.
— 4 —
2 Turn the cam to the
direction of arrow.