Sony SLV-7700KME, Service Manual

Page: 97 / 135

7-3
2-3. POWER SUPPLY CHECK
2-3-1. Output Voltage Check (PS-418 Board)
Mode E-E
Measuring
Digital voltmeter
instrument
SW 5V check
Measurement
CN101 pin
1
point
Specified
5.3 ± 0.3 Vdc
value
D 6V check
Measurement
CN101 pin
5
, CN103 pin
7
point
Specified
5.9 ± 0.3 Vdc
value
+ F check
Measurement
CN101 between pin
6
to
8
point
Specified
4.6 ± 0.7 Vdc
value
DC –30V check
Measurement
CN101 pin
7
point
Specified
– 30 ± 3.0 Vdc
value
PS 13V check
Measurement
CN102 pin
1
,
2
point
Specified
13.2 ± 1.0 Vdc
value
MTR 12V check
Measurement
CN102 pin
3
,
4
point
Specified
12 ± 1.0 Vdc
value
SW 12V check
Measurement
CN102 pin
8
, CN103 pin
1
point
Specified
12 ± 0.5 Vdc
value
AU –13V check
Measurement
CN102 pin
9
point
Specified
– 13 ± 0.5 Vdc
value
SW –13V check
Measurement
CN103 pin
4
point
Specified
– 13 ± 0.5 Vdc
value
MTR 10V check
Measurement
CN103 pin
9
point
Specified
10 ± 1.0 Vdc
value
[Check Method]
1)
Check that each voltage satisfied the specified value.
Note : AC input voltage = 240 ± 5 Vac
2-4. VIDEO-CD SYSTEM ADJUSTMENTS
• CD Block is basically to operate without adjustment.
Therefore, check each item in order given.
• Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
• Use an oscilloscope with more than 10M
Ω
impedance.
• Clean the object lens by an applicator with neutral detergent when
the signal level is low than specified value with the following
checks.
[Adjustment Sequence]
1)
S-Curve check
2) RF level check
3) E-F Balance (Traverse) check
4) RF PLL Free-run Frequency check
5) Clock Adjustment
2-4-1. S-Curve Check (BD-21 Board)
Signal Reference disc
Measurement + : TP FE
point – : TP VC
Measuring
Oscilloscope
instrument
Specified
S-curve is symmetrical between A and B.
value
[Check Method]
1)
Connect oscilloscope to test point TP (FE) on BD-21 board.
2) Connect between test point TP (FEI) and TP (VC) by lead wire.
3) Turned Power switch on.
4) Put disc (YEDS-18) in and turned Power switch on again and
actuate the focus search. (actuate the focus search when disc
table is moving in and out.)
5) Check the oscilloscope waveform (S-curve) is symmetrical
between A and B.
And confirm peak to peak level within 3 ± 1 Vp-p.
6) After check, remove the lead wire connected in step 2.
Note :
• Try to measure several times to make sure than the ratio
of A : B or B : A is more than 10 : 7.
• Take sweep time as long as possible and light up the
brightness to obtain best waveform.
Fig. 7-2-6.
symmetry
within 3
±
1 Vp-p
A
B
S-curve waveform