Sony CFD-V8L, Service Manual

Page: 11 / 46

11
CFD-V8L
• Repeat the procedures in each adjustment several times, and
the frequency coverage and tracking adjustments should be
finally done by the trimmer capacitors.
LW IF ADJUSTMENT
Adjust for a maximum reading on level meter.
T2 455kHz
LW FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter.
L4 145kHz
CT4, CV2 300kHz
LW TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L3 160kHz
CT3, CV3 260kHz
FM IF ADJUSTMENT
Adjust for a maximum reading on level meter.
T1 10.7MHz
FM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter.
L2 87.0MHz
CT2 108.3MHz
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L1 87.0MHz
CT1 108.3MHz
Adjustment Location : Main board (See page 12)
CD SECTION
How to put the set into CD Test Mode
1. Set the function switch to power off.
2. Set the function switch to CD.
3. Set Test mode by momentarily shorting both of the IC801 51pin
to GND. (Shorting the terminals momentarily is sufficient).
The set is into CD test mode (88 is displayed).
4. Turn the power off to release test mode.
R812
R811
R809
R810
R851
C844
C
8
C8
4
R815
R814
R813
C801
IC801
R816
R
C810
C317
W
321
C802
GND
51pin
TEST mode : momentarily short
[MAIN BOARD] (Conductor side)
CD section adjustments are done automatically in this set.
In case of operation check, confirm that focus bias.
Focus Bias Check
1. Connect the oscilloscope between TP (RF) and GND on CD
board.
2. Insert the disc (YEDS-18). (Part No. : 3-702-101-01)
3. Press the 7 button two times (LPC ON).
4. 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.
• RF Signal Reference Waveform (eye pattern)
When observing the eye pattern, set the oscilloscope for AC
range and raise certical sensitivity
RF level
0.7 – 1.0 Vp-p (LPC ON)
1.0 – 1.4 Vp-p (LPC OFF)
VOLT/TV : 200mV
TIME/DIV : 500 nS
IC701
R729
R708
C736
C734
R709
C705
R704
R702
R711
R710
R703 R705 R701
C703
TP
(RF)
C731
R706
JC703
C743
C7
C742
C
707
9
38
732
JW708
W
709
J
C74
oscilloscope
(AC range)
[CD BOARD] (Conductor side)
(GND)
TP (RF)