Sony ICF-CD2000 Service Manual page 18

CD SECTION
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: DC6 V in battery terminal
VOLUME knob : Minimum
MEGA BASS switch : OFF
Before Beginning Adjustment
Set the equipment to service mode (See page 11) and check the
following. If there is an error, repair the equipment.
• Checking of the sled motor
1. Open the upper panel.
2. Press the > and .
up can move smoothly without sluggishness or abnormal noise
in innermost periphery → outermost periphery → innermost
periphery
> : The optical pick-up moves outwardly.
: The optical pick-up moves inwardly.
.
• Checking of focus searching
1. Open the upper panel.
[CD ]
2. Press the u 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.
VCC Check
Use a SUM-3 battery for VCC check
Check Procedure:
MAIN board
Each TP
(See page 20)
1. Set the equipment to service mode stop state. (See page 11)
2. Connect the digital voltmeter to each test point on the MAIN
board as follows.
3. Confirm that the reading on digital voltmeter satisfy specified
value of each test point.
Test point
+3 V
+3.4 V
DV
MDV
OPDV
POWER +B
PRE +B
PRE VC
4. After the completion of adjustment, reset service mode. (See
page 11)
Check Location: MAIN Board (See page 20)
keys and check that the optical pick-
digital voltmeter
(DC range)
+
–
Specified value
3.2 V
3.2 V
4.5 V
2.6 V
1.75 V
3.8 V
3.8 V
1.6 V
Tracking Balance Check
Condition:
• Hold the set in horizontal state.
Check Procedure:
MAIN board
TP (TE)
TP (VC)
(See page 14)
1. Put the disc (YEDS-18).
2. Connect the oscilloscope to TP (TE) and TP (VC) on the MAIN
board.
3. Set the equipment to service mode stop state. (See page 11)
4. Confirm that the waveform on the oscilloscope becomes up/
down symmetrical with an axis of 0 V.
0 V
5. After the completion of adjustment, reset service mode. (See
page 11)
Check Location: MAIN Board (See page 20)
– 18 –
oscilloscope (DC range)
+
–
Note: Take long sweep time
for easy monitoring.
A
0.7 – 1.7 Vp-p 0 V
B
A=B A=B
A
B