Read Sony BMZ-K7D / CX-BK7 Service Manual online
CX-BK7
37
37
SECTION 6
ELECTRICAL ADJUSTMENTS
Precaution
1. The adjustment should be performed with the rated power sup-
ply voltage.
2. The adjustments should be performed for both L-ch and R-ch.
0 dB = 0.775 V
DECK SECTION
Precaution
1.
DVD block is basically designed to operate without adjustment. There-
fore, check each item in order given.
fore, check each item in order given.
2.
Use DVD reference disc unless othermise indicated.
[DVD reference disc]
TDV-520CSO (DVD-SL): PART No. J-2501-236-A
LUV-P01 (CD):
[DVD reference disc]
TDV-520CSO (DVD-SL): PART No. J-2501-236-A
LUV-P01 (CD):
PART No. 4-999-032-01
TDV-540C (DVD-DL):
PART No. J-2501-235-A
Note:
Do not use existing test disc for DVD.
3.
Use an oscilloscope with more than 10M
Ω
impedance.
4.
Clean the object lens by an applicator with neutral detergent when the
signal level is low than specified value with the following checks.
signal level is low than specified value with the following checks.
AUTO SERVO ADJUSTMENT
After parts related to the servo circuit (RF amplifier (IC001), DSP
(IC509), motor driver (IC501), EEPROM (IC903) so on) are re-
placed, re-adjusting the servo circuit is necessary. Select “ALL” at
“1. DRIVE AUTO ADJUSTMENT” (Refer to page 30 in TEST
MODE) and adjust DVD-SL (single layer), CD and DVD-DL (dual
layer).
(IC509), motor driver (IC501), EEPROM (IC903) so on) are re-
placed, re-adjusting the servo circuit is necessary. Select “ALL” at
“1. DRIVE AUTO ADJUSTMENT” (Refer to page 30 in TEST
MODE) and adjust DVD-SL (single layer), CD and DVD-DL (dual
layer).
VIDEO LEVEL CHECK
Purpose:
This adjustment is made to satisfy the NTSC standard, and if not
adjusted correctly, the brightness will be too large or small.
This adjustment is made to satisfy the NTSC standard, and if not
adjusted correctly, the brightness will be too large or small.
Procedure:
1. Connect an oscilloscope to MONITOR VIDOE OUT jack
1. Connect an oscilloscope to MONITOR VIDOE OUT jack
(J802) on the SP board.
2. Load a DVD reference disc.
3. Check the video signal level is 1.00
3. Check the video signal level is 1.00
±
0.05Vp-p.
SP board
MONITOR VIDEO OUT
jack (J802)
MONITOR VIDEO OUT
jack (J802)
75
Ω
Oscilloscope
set
1.00
±
0.05 Vp-p
(WHITE 100%)
DVD SECTION
RECORD BIAS ADJUSTMENT
Procedure:
1.
1.
Record mode
2.
Mode: Playback
i-Bass OFF
BASS 0
TREBLE 0
i-Bass OFF
BASS 0
TREBLE 0
3.
Confirm playback the signal recorded in step 1 become
adjustment level as follows.
adjustment level as follows.
4.
If these levels do not adjustment level, adjustment the SFR452
(L-ch) and SFR451 (R-ch) to repeat steps 1 and 4.
(L-ch) and SFR451 (R-ch) to repeat steps 1 and 4.
Adjustment level: Playback output of 315 Hz to playback out-
put of 10 kHz: 0
±
1.0 dB (0
±
4.5mV).
Adjustment Location: DECK board
+
–
–
set
recorded
portion
portion
SP board
FRONT SPEAKER
terminal (JK502)
FRONT SPEAKER
terminal (JK502)
level meter
attenuator
set
MAIN board
MD (AUX) IN jack (JK602)
MD (AUX) IN jack (JK602)
1) 315 Hz
2) 10 kHz
2) 10 kHz
50 mV (–23.8 dB)
600
Ω
blank tape
CN-123
CN-123
AF OSC
— DECK BOARD (Component Side) —
SFR451
REC Bias
Adjustment
(R-ch)
SFR452
REC Bias
Adjustment
(L-ch)
Ver 1.2
Checking Location:
Connection:
Procedure:
1.
1.
Connect an oscilloscope to test point 1 pin and 3 pin
of CN901 on the MB03 board.
of CN901 on the MB03 board.
2.
Turn the power on.
3.
Put the disc (LUV-P01) (Part No.:4-999-032-01) (CD)
in to playback.
in to playback.
4.
Conf
5.
Put the disc (TDV-520CSO) (Part No.:J-2501-236-A)
(DVD) in to playback.
(DVD) in to playback.
6. Perform confirmation in the same manner as step 4.
irm that oscilloscope waveform is clear and check RF
signal level is correct or not.
Note:
A clear RF signal waveform means that the shape “
◊
” can be
clearly distinguished at the center of the waveform.
RF signal waveform
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
TIME/DIV: 500 ns
CD: 1.05
±
0.2 Vp-p
DVD: 1.09
±
0.2 Vp-p
RF LEVEL CHECK
+
–
–
oscilloscope
CN901
1
pin
CN901
3
pin
MB03 board
CN901
1
7
– MB03 Board (Side A) –
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