Sony ICF-CD855V Service Manual page 15

CD SECTION
Perform all CD section check in the test mode.
FOCUS BIAS CHECK
Procedure:
1. Connect the oscilloscope to TP (RF) and TP (VREF) on the
CD board.
2. Insert the test disc (YEDS-18). (Part No. 3-702-101-01) (CD)
3. While playing the CD, set the CD test mode (Refer to CD
TEST MODE (See page 11)) (Automatic adjustment value is
held at this time).
4. Press the CD u button. (LPC ON) (700 is displayed on the
LCD)
5. Confirm 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.
6. Press the CD u button. (LPC OFF) (800 is displayed on the
LCD)
7. Perform confirmation in the same manner as step 5.
8. Press the OFF x button.
[SLEEP]
9. Press the button in the state where 200 or 100 are
displayed on the LCD, and release the CD test mode.
10. Change the test disc (TCD-W082L). (Part No. J-2502-063-2)
(CD-RW)
11. Perform confirmation in the same manner as step 2 to 7.
• RF signal reference waveform (eye pattern)
VOLT/DIV: 0.2 V (with the 10: 1 probe in use.)
TIME/DIV: 500 ns
CD:
1.1 ± 0.2 Vp-p (LPC ON)
1.2 ± 0.4 Vp-p (LPC OFF)
CD-RW:
1.1 ± 0.2 Vp-p
When observing the eye pattern, set the oscilloscope
for AC range and raise vertical sensitivity.
Connecting Location:
– CD BOARD (Conductor Side) –
TP
(RF)
IC702
TP
(TE)
IC701
TP
(VREF)
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ICF-CD855V