HCD-GZR7D/GZR8D/GZR9D
40
Video Level Check (VIDEO BOARD)
Purpose
This adjustment is made to satisfy the NTSC standard, and if not
adjusted correctly, the brightness will be too large or small.
oscilloscope
set
J902
VIDEO OUT
75
Ω
+
–
Procedure:
1. Connect oscilloscope to VIDEO outjack.
2. Load a DVD reference disc playback.
3. Check the video signal level is 1.00±0.07Vp-p.
1.00 ± 0.07 Vp-p
(WHITE 100%)
VIDEO SECTION
1. Demagnetize the record/playback head with a head
demagnetizer.
2. Do not use a magnetized screwdriver for the adjustments.
3. After the adjustments, apply suitable locking compound to
the parts adjust.
4. The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
5. The adjustments should be performed in the order given in
this service manual. (As a general rule, playback circuit
adjustment should be completed before performing recording
circuit adjustment.)
6. The adjustments should be performed for both L-CH and
R-CH.
7. Switches and controls should be set as follows unless
otherwise specifi ed.
• Test Tape
Tape
Signal
Used for
P-4-A063
6.3 kHz, –10 dB
Azimuth Adjustment
Record/Playback Head Azimuth Adjustment
DECK A
DECK B
Note:
Perform this adjustments for both decks
Procedure:
1. Mode: Playback
+
–
level meter
test tape
P-4-A063
(6.3 kHz, –10 dB)
MAIN board
IC101
pin
XI
(L-CH)
pin
RM
(R-CH)
MAIN board
IC101
pin
U
(GND)
2. Turn the adjustment screw and check output peaks. If the
peaks do not match for L-CH and R-CH, turn the adjustment
screw
so that outputs match within 1dB of peak.
screw
position
L-CH
peak
within
1 dB
output
level
L-CH
peak
R-CH
peak
within
1 dB
screw
position
R-CH
peak
DECK SECTION
0 dB = 0.775V
