Sony TRINITRON KV-VF21M70, Service Manual

Page: 87 / 116

– 99 –
X’tal OSC CHECK
Mode PB
Signal Alignment tape, Stair step
Measurement Point MA10 board Q823 emitter(NTSC)
IC802
%ª
pin(PAL)
Measurement Equipment Oscilloscope
Specified Value 500
±
200mVp-p
Check: 1)Confirm the frequency is 3.579545MHz
±
82Hz(NTSC), and
4.433619MHz
±
100Hz(PAL).
2)Confirm the waveform amplitude is 500
±
200mVp-p.
Fig.3-3
SYNC AGC CHECK
3.579545MHz
±
82Hz (NTSC)
4.433619MHz
±
100Hz (PAL)
500
±
200mVp-p
Mode E-E
Signal Color bar
Measurement Point MA10 board Q830 emitter
Measurement Equipment Oscilloscope
Specified Value 1.0
±
0.1Vp-p
Check:
Confirm the waveform amplitude is 1.0
±
0.1Vp-p.
Fig.3-4
CARRIER DEVIATION CHECK
1.0
±
0.1Vp-p
Mode E-E
Signal Color bar
Measurement Point MA10 board IC802
!•
pin
Measurement Equipment Spectrum Analyzer
Specified Value f
2
-f
1
=1.00
±
0.08MHz
Check: Confirm f
2
-f
1
=1.00
±
0.08MHz
Confirm f
1
=3.40
±
0.13MHz(NTSC), and
3.80
±
0.13MHz(PAL)
Fig.3-5
WHITE/DARK CLIP CHECK
f
1
f
2
Mode E-E
Signal Color bar
Measurement Point MA10 board IC802
#¶
pin
Measurement Equipment Oscilloscope
Specified Value 190
±
20%(White), 55
±
20%(Dark)
Preparation: Add 3.3k
Ω
resistor between IC802
$™
pin and GND.
Check: Taking the height from sync to white level as 100%, check
white clip and dark clip.
100%
White clip
Dark clip
Fig.3-6