Sony CDP-997 Service Manual page 16

CDP-997 |
[Focus Gain Check]
1.
w
Low focus gain
High focus gain
Keep the set horizontal.
Keep the set horizontal, or this adjustment cannot be
performed due to the gravity against the 2-axis device.
Insert disc (YEDS-18: the Sth song) and press [> PLAY
button.
Connect the oscilloscope to IC101 @ terminal on BD board.
Check waveforms of the oscilloscope to shape ones as
shown in figure below.
Measuring points:
BD board
es
1C101 @ (focus)
1C101 @ (tracking)
TP (VC)
VOLT/DIV : 100 mV
Normal TIME/DIV :2mS
100mV
Ov
VOLT/DIV : 100 mV
TIME/DIV :2mS
OV
VOLT/DIV : 100 mV
TIME/DIV :2mS
Ov
[Tracking Gain Check]
1.
2.
Oscilloscope
(DC range)
o
Ot —-—7—-——0 +
EES ie
Normal
Low tracking gain .
VOLT/DIV : 500mV
TIME/DIV :2mS
OV
VOLT/DIV : 500mV
TIME/DIV :2mS
OV
VOLT/DIV : 500mV
TIME/DIV :2mS
High tracking gain
(The fundamental wave is higher than when gain is low.)
ov