Sharp 14A1-RU, Service Manual

Page: 9 / 42

9
14A1-RU
14A2-RU
9-2
9-1
No.
Adjusting point
Adjusting procedure/conditions
W
aveform and others
SUB-TINT (I
2
C
BUS CON- TROL)
1
.
Receive the "NTSC3.58 Colour Bar" signal through A
V
in.
2.
Connect the oscilloscope to
TP853 (Pin (5) of
P882) BLUE-OUT
.
»
Range
: 100mV/div
. (AC)(Use Probe 10:1)
»
Sweep time
:
10
µ
sec/div
.
3.
Call the "SUB-TINT" mode in service mode.
Ad-
just the "SUB-TINT" bus data to obtain the wave- form shown as Fig. 9.
4.
Clear the SER
VICE mode.
1
NTSC CHROMA
ADJUSTMENT
No.
Adjusting point
Adjusting procedure/conditions
W
aveform and others
BEAM PRO- TECT
OR
1.
Receive "Monoscope Pattern" signal.
2.
Set CONTRAST MAX.
3.
Set BRIGHT MAX.
4.
During the Collector & Emitter of Q883/5/7 short, make sure the protector ON and switch to standby mode.
1
* Select one of Q883/5/7 to do
each short test.
H, V PROTEC- TO
R
1.
Receive "Monoscope Pattern" signal.
2
.
Connect output of Bias Box to D607 cathode (R606 side).
3.
Set voltage of Bias Box to 18V and make sure the protector is not work.
4.
Set voltage of Bias Box to 27V
, and make sure
the protector is work.
2
Other protectors
1.
Once finish rectified Electrolytic Capacitor short testing in +B line, check all possible damaged components on +B line. (Use random selected set for inspection)
3
PROTECT
OR OPERA
TION CHECKING
No.
Adjusting point
Adjusting procedure/conditions
W
aveform and others
VIDEO AND AUDIO OUTPUT CHECK
1.
Receive the "P
AL
Color Bar" signal (100% White
Color Bar
, Sound 400 Hz 100% Mod.)
2.
T
erminate the V
ideo output with a 75 ohm imped-
ance.
Make sure the output is as specified (1.0
Vp-p
±
3 dB).
3.
T
erminate the
Audio output with a 10k ohm im-
pedance.
Make sure the output is as specified
(1.76 Vp-p
±
3 dB).
1
VIDEO AND AUDIO INPUT CHECK
1.
Using the
TV/A
V key on the remote controller
,
make sure that the modes change in order of
TV
,
A
V1,
A
V2 &
TV again and the video & audio out-
put are according to the input terminal for each mode.
2
A/V INPUT
AND OUTPUT CHECKING
W
Y
Cy
G
M
g
R
B
SAME LEVEL
Fig. 9
HORIZONT
AL
AND VERTICAL
DEFLECTION LOOP
ADJUSTMENT
No.
Adjusting point
Adjusting procedure/conditions
W
aveform and others
V
-SLOPE(I
2
C
BUS CON- TROL) V
-CENTER (I
2
C
BUS CON- TROL) V -
AMP
(I
2
C
BUS CON- TROL) S-CORREC- TION
(I
2
C BUS
CONTROL) H - CENTER
1.
Receive Monoscope Pattern Signal.
2.
Call the "V
-LIN" mode.
3.
Increase or decrease "V
-LIN" by V
olume key till
the horizontal line in the center of monoscope is just at the position where the blanking starts.
1.
Call the "V
-CENT" mode.
2. Increase or decrease "V
-CENT" by V
olume key
till the picture is centered.
1.
Call the "V
-AMP" mode.
2.
Increase or decrease "V -
AMP" by V
olume key
to set overscan of 9.5% typical. Adjustment Spec 9.5% range +1% -0%.
FIXED DA
T
A, NO NEED T
O
ADJUST
.
1.
Call the "H-CENT" mode.
2.
Increase or decrease "H-CENT" by V
olume key
to center the picture horizontal.
1 2 3 4 5
Focus adjustment
1.
Receive the "Monoscope Pattern" signal.
2.
Press R/C to set Picture NORMAL condition.
3.
Adjust the focus control to get the best focus.
6
P
A
L
CHROMA
ADJUSTMENT
No.
Adjusting point
Adjusting procedure/conditions
W
aveform and others
SUB COLOUR (I
2
C BUS
CONTROL)
1.
Receive the "P
AL
Colour Bar" signal.
2.
Press R/C to set Picture Normal condition.
3
.
Connect the oscilloscope to Red cathode(TP854).
»
Range
: 20 V/div
. (AC) (Using 10:1 probe)
»
Sweep time
:
10
µ
sec/div
.
4
.
Using the R/C call "SUB COL" in SER
VICE mode.
Adjust SUB COLOUR bus data, so that the 75% White & Red portions of P
A
L
Colour Bar be at the
same level shown as
Fig. 8
.
5.
Clear the SER
VICE mode.
1
Cy
G
B
W
Y
100%W
75%
Mg
R
Fig. 8