Sharp 21J-FG1RU, Service Manual

Page: 24 / 75

21J-FG1RU
3 – 21
8. NTSC CHROMA ADJUSTMET
9. SECAM CHROMA ADJUSTMENT
No. Adjustment point Adjustment procedure/conditions Waveform and others
SUB-TINT 1) Receive the "NTSC3.58 Colour Bar" signal thru
AV in.
2) Connect the oscilloscope to B-Amp Transistor
Base (TP853 ) .
Range : 100mV/Div. (AC)(Use Probe 10:1)
Sweep time : 10
µ
sec/Div.
3) In Service mode, go to V07 , press R/C Y-
mute(Hex E4) or FLASHBACK Key.
4) Call the " V07 " data in service mode. Adjust the
" V07 " bus data to obtain the waveform shown as
Fig. 1-1.
5) Disable Y-Mute by pressing key(Hex E4) or
then clear the SERVICE mode.
1
Fig. 1-1
W Y Cy G Mg R B
FLASHBACK,
(I 2 C BUS CONTROL)
No. Adjustment point Adjustment procedure/conditions Waveform and others
SECAM
BLACK LEVEL
R-Y/B-Y
(I
2
C BUS
CONTROL)
1) Receive “SECAM COLOUR BAR” signal.
2) In the service mode, select service data
V14 .
3) Connect oscilloscope to TP 801 .
Range : 20mV/Div. (AC)(Use Probe 10:1)
Sweep time : 20
µ
sec/Div.
4) Adjust the V14 so that the offset of R-Y is mini-
mum, shown in Fig 2-1(b) , it means adjust the
offset of between No signal line and Signal line to
minimum.
5) In the service mode, select service data V15 .
6) Connect oscilloscope to TP 801 .
Range : 20mV/Div. (AC)(Use Probe 10:1)
Sweep time : 20
µ
sec/Div.
7) Adjust the V15 so that the offset of B-Y to mini-
mum, shown in Fig 2-2(b) , it means adjust the
offset of between No signal line and Signal line to
minimum.
1
Fig 2-1(a)
Offset
Offset
Fig 2-1(b)
Fig 2-2(a)
Fig 2-2(b)