Yc Board - Sony Trinitron KV-21V4A Service Manual

[ Specified Input/Output Level Impedance ]
Input/Output terminal
Video input Pin jack
Input signal : 1Vp-p, 75Ω, unbalanced
VIDEO LINE OUT Pin jack
Output siganl : 1Vp-p, 75Ω, unbalanced
AUDIO LINE IN Pin jack
Input level
Input impedance : More than 47kΩ
AUDIO LINE OUT Pin jack
Specified output : -7.5dBs
Load impedance : More than 10kΩ
[ Adjustment Sequence ]
Make the electrical adjustment in the following sequences.
Checking power supply
Servo system adjustment Servo system adjustment Tuner system adjustment
Video system adjustment
Sync negative
Sync negative
: -7.5dBs
(0dBs=0.775Vrms)
At 47kΩ loaded.
Audio system adjustment
2-1. MA BOARD ADJUSTMENT
RV301
AUDIO
L005
BIAS
REC BELL 2
REC C SECAM
REC
BELL 1
L003
RV652 L004
PB BELL
REC C PAL
1. Recording bias adjustment
Mode
Signal
Measurement
Equipment
Adjustment
Element
Specified Value
Note : Tape path adjustment should have been completed.
1) Input signal of 400Hz, -27.5dBs.
2) Make recording.
3) Set the AUDIO LINE IN signal to 7kHz, -27.5dBs and
make recording.
4) Playback a recorded portion and measure output levels
at 400Hz and 7kHz.
5) Confirm that the 7kHz playback signal level is within a
range of 0 ± 2dB against the 400Hz playback signal
level. When beyond this range, adjust RV301 and
repeat the step (1) through (5).
– 62 –
RV502
SWITCHING POSITION
IC501
RV001
VR002
SYNC GATE
MA BOARD
- component side -
Recording and playback (SP mode)
400Hz, -27.5dBs
7kHz, -27.5dBs
Audio level meter
RV301
0 ± 2dB