SONY ICFCD873
Instrukcja Serwisowa

CD SECTION
Note: Tracking Balance Adjustment and Tracking Gain Adjustment are done automatically in this set.

Focus Bias Adjustment This adjustment is to be done when the optical block is replaced. Connection:
oscilloscope (AC range) MAIN board TP503 (RF) TP504 (VREF) + �

TEST MODE 1. Press the CD LID OPEN/CLOSE DET switch (S424) on the PUSH SWITCH board. 2. Under standby condition (when the clock appear in the display), short the BP (CD TEST AUTO).
Note: If the power is supplied to the microprocessor once, it is backed up for 3 minutes, therefore the TEST mode will not be activated within 3 minutes even if the power is turned on again. In this case, short instantaneously the BP (CD TEST MANUAL).

3. Press the ^ key, and the focus search is repeated. At this time, check that the optical pick-up objective lens moves smoothly without a sticking or noise. 4. Load the test disc (YEDS-18: Part No. 3-702-101-01), and perform automatic adjustment after the focus search succeded. 5. After automatic adjustment is finished, move the sled motor to the center. At this time, keep pressing the + and = keys to confirm that optical pick-up moves smoothly via most inside track � most outside track � most inside track without a sticking or noise. 6. Confirm the traverse waveform. 7. Press the [WAKE UP TRACK] key. 8. The tracking servo and the sled servo are turned on, the mute is cancelled. 9. Playback the 2nd track. 10. Adjust the RF and jitter waveforms. Connecting points: MAIN Board (See page 13)

Adjustment Procedure: 1. Connect the oscilloscope to TP504 (VREF) and TP503 (RF) on the MAIN board. 2. Insert the test disc (YEDS-18: Part No.3-702-101-01) and press ^ key to play. 3. Move the optical pick-up to the music area on the disc to enable easy visibility of the eye pattern by + or = key pressing. 4. Adjust RV501 so that the oscilloscope waveform is as shown in the figure below (eye pattern). 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: 0.2 V TIME/DIV: 500 ns 1.3 ± 0.5 Vp-p

When observing the eye pattern, set the oscilloscope for AC range and raise vertical sensitivity.

Adjustment Location: MAIN Board (See page 13)

� 10 �