Electrical Adjustments - Sony D-ES51 Service Manual

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3 7 63 1515 0
Precautions for Adjustment
1. Before beginning adjustment, set the equipment to service
mode.
After the completion of adjustment, be sure to reset the ser-
vice mode.
For more information, see "Service Mode (service program) "
on page 10.
2. Perform adjustments in the order given.
3. Use YEDS-18 disc (Part No.: 3-702-101-01) unless otherwise
indicated.
4. Power supply voltage requirement: DC2.5 V in battery termi-
nal
VOLUME knob : Minimum
SOUND switch : OFF
RESUME switch : OFF
ESP switch
AVLS switch
HOLD switch
Before Beginning Adjustment
Set the equipment to service mode (See page 10) and check the
following. If there is an error, repair the equipment.
• Checking of the sled motor
1. Disengage the buckles and open the upper panel.
2. Press the + and = keys and check that the optical pick-
up can move smoothly without sluggishness or abnormal noise
in innermost periphery n outermost periphery n innermost
periphery
+ : The optical pick-up moves outwardly.
=: The optical pick-up moves inwardly.
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L 13942296513
• Checking of focus searching
1. Disengage the buckles and open the upper panel.
2. Press the ^ key. (Focus searching operation is activated
continuously.)
3. Check the object lens of the optical pick-up for smooth up/
down motion without sluggishness or abnormal noise.
4. Press the p key.
Check that focus searching operation is deactivated. If not,
again press the p key slightly longer.
+B Voltage Adjustment
Adjustment Procedure:
MAIN board
TP401 (VCC)
TP427 (VCPU)
(See page 13)
1. Set the equipment to service mode stop state. (See page 10.)
2. Connect the digital voltmeter to TP401 (VCC) of the MAIN
board.
3. Adjust RV401 on the MAIN board so that the reading on digi-
tal voltmeter goes 2.73-2.77 V.
4. Connect the digital voltmeter to TP427 (VCPU) on the MAIN
board, and confirm that a reading of digital voltmeter is 2.97-
3.07 V.
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5. After the completion of adjustment, reset service mode. (See
page 10.)
Adjustment Location: MAIN board (See page 13.) .
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ELECTRICAL ADJUSTMENTS

: OFF
: NORMAL
: OFF
digital voltmeter
(DC range)
+
–
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SECTION 5
8
Focus bias Check
Condition:
• Hold the set in horizontal state.
Check Procedure:
1. Set the equipment to service mode stop state. (See page 10.)
2. Connect the oscilloscope to the test point TP522 (RFO) of the
MAIN board.
3. Move the optical pick-up to the center by pressing the +
and = keys.
4. Put the disc (YEDS-18).
5. Press the ^ key.
From focus searching, focus is turned ON while entering
CLV drawing-in mode. Tracking and sled are turned OFF.
6. Press the PLAY MODE key. (Both tracking and sled are turned
ON.)
7. Check the oscilloscope waveform is as shown below.
A good eye pattern means that the diamond shape (≈) in the
center of the waveform can be clearly distinguished.
RF SIGNAL REFERENCE WAVEFORM (EYE PATTERN)
VOLT/DIV : 200 mV (With the 10:1 probe in use)
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3 6 7 1 3
TIME/DIV : 500 ns
To watch the eye pattern, set the oscilloscope to AC range and
increase the vertical sensitivity of the oscilloscope for easy watch-
ing.
8. Stop revolving of the disc motor by pressing the p key.
9. After the completion of adjustment, reset service mode. (See
page 10.)
Check Location: MAIN Board (See page 13.)
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– 11 –
2 9 9 4 2 8
oscilloscope
(AC range)
MAIN board
2 k Ω
TP522 (RFO)
+
TP520 (VC)
–
(See page 13)
1 5 0 5 8 2 9 9 4
m
co
9 9
2 8 9 9
RF level
+ 0.2
1.0 V
–0 .15