Electrical Adjustment - Sony D-EJ119 Service Manual

D-EJ119/EJ120/EJ121
The CD section adjustments are done automatically in this set.
In case of operation check, confirm that RF level.
Precautions for Check
1. Perform check in the order given.
2. Use YEDS-18 disc (Part No.: 3-702-101-01) unless otherwise
indicated.
3. Power supply voltage requirement : DC4.5 V in DC IN jack.
[VOL] button
: Minimum
. switch : OFF
HOLD
8
SECTION 4

ELECTRICAL ADJUSTMENT

(J401)
RF Level Check
Condition:
• Hold the set in horizontal state.
Connection:
MAIN board
TP601 (RF)
TP605 (AGND)
Procedure:
1. Connect the oscilloscope to the test points TP601 (RF) and
TP605 (AGND) on the MAIN board.
2. Set a disc. (YEDS-18)
3. Press the u button.
4. Check the oscilloscope waveform is as shown below.
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 : 100 mV (With the 10:1 probe in use)
TIME/DIV : 500 ns
To watch the eye pattern, set the oscilloscope to AC range and
increase the vertical sensitivity of the oscilloscope for easy watch-
ing.
Stop revolving of the disc motor by pressing the x button.
5.
Checking Location:
MAIN BOARD (SIDE B)
IC301
TP601
(RF)
TP605
(AGND)
oscilloscope
(AC range)
+
–
RF level
0.45 to 0.65 Vp-p
IC601