Read Sony ICF-CD815 Service Manual online
14
ICF-CD815
– MAIN Board (Conductor Side) –
TP706
(RF)
TP702
(VREF)
CD SECTION
CD section adjustments are done automatically in this set.
In case of operation check, confirm that focus bias.
In case of operation check, confirm that focus bias.
FOCUS BIAS CHECK
Connection:
Procedure:
1. Connect a oscilloscope to TP706 (RF) and TP702 (VREF) on
the MAIN board.
2. Insert the CD test disc (PATD-012). (Part No. 4-225-203-01)
3. Press the
3. Press the
u
CD
button.
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
thecenter of the waveform can be clearly distinguished.
RF Signal Reference Waveform (Eye Pattern)
Checking Location:
VOLT/DIV: 0.2 V (with the 10: 1 probe in use.)
TIME/DIV: 500 ns
TIME/DIV: 500 ns
1.1
±
0.3 Vp-p
When observing the eye pattern, set the oscilloscope
for AC range and raise vertical sensitivity.
for AC range and raise vertical sensitivity.
+
–
–
MAIN board
TP706 (RF)
TP702 (VREF)
oscilloscope
(AC range)
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