Electrical Adjustments; Dvd Section; Deck Section - Aiwa CX-BK7 Service Manual

ELECTRICAL ADJUSTMENTS

DVD SECTION

Precaution
1. DVD block is basically designed to operate without adjustment. There-
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): 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 10MΩ 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.
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).
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.
Oscilloscope
75 Ω
set
SP board
MONITOR VIDEO OUT
jack (J802)
Procedure:
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 ± 0.05Vp-p.
1.00 ± 0.05 Vp-p
(WHITE 100%)
SECTION 6

DECK SECTION

0 dB = 0.775 V
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.
RECORD BIAS ADJUSTMENT
Procedure:
1. Record mode
MAIN board
MD (AUX) IN jack (JK602)

1) 315 Hz
50 mV (–23.8 dB)

2) 10 kHz

AF OSC
600 Ω
attenuator
set
2. Mode: Playback
i-Bass OFF
BASS 0
TREBLE 0
recorded
level meter
portion
set
SP board
FRONT SPEAKER
terminal (JK502)
3. Confirm playback the signal recorded in step 1 become
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.
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
— DECK BOARD (Component Side) —
SFR451 SFR452
REC Bias REC Bias
Adjustment Adjustment
(R-ch) (L-ch)
blank tape
CN-123
+
–
37 37
CX-BK7