Sharp 14BM2, Service Manual

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9-1 9-2
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14BM2, 14BM2S/G 20BM2, 20BM2S/G 21BM2, 21BM2S/G
HORIZONTAL, VERTICAL, DEFLECTION LOOP AND FOCUS ADJUSTMENT
NO. Adjustment part Adjusting procedure and conditions Waveform and others
1
2
3
4
5
V-SLOPE
(I
2 C BUS
CONTROL)
V-SHIFT-50
(I
2 C BUS
CONTROL)
V-AMP 50
(I
2 C BUS
CONTROL)
S-CORRECTION
(I
2 C BUS
CONTROL)
H-SHIFT (50)
(H-CENTER)
(I
2 C BUS
CONTROL)
1. Receive Monoscope Pattern Signal.
2. Call the “V-LIN” mode.
3. Increase or decrease “V-LIN” by Volume 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 Volume key
till the picture is centered.
1. Call the “V-AMP” mode.
2. Increase or decrease “V- AMP” by Volume key
to set overscan of 9.5% typical.
Adjustment Spec 9.5% range +1% -0%.
FIXED DATA, NO NEED TO ADJUST.
1. Call the “H-CENT” mode.
2. Increase or decrease “H-CENT” by Volume key
to center the picture horizontal.
PAL CHROMA ADJUSTMENT
NO. Adjustment part Adjusting procedure and conditions Waveform and others
1 SUB COLOUR
(I
2
C BUS
CONTROL)
1. Receive the “PAL Colour Bar” signal.
2. Press R/C to set Picture Normal condition.
3. Connect the oscilloscope to Red cathode.
»
Range : 20 V/Div. (AC) (Use 10:1 probe)
»
Sweep time : 10
µ
sec/Div.
4. Using the R/C call “SUB COL” in SERVICE
mode. Adjust SUB COLOUR bus data, so that
the 75% White & Red portions of PAL Colour
Bar be at the same level shown as Fig. 8.
5. Clear the SERVICE mode.
1 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 focusing.
Cy G B
W Y 100%W
75%
Mg R
Fig. 8
NTSC CHROMA ADJUSTMENT
NO. Adjustment part Adjusting procedure and conditions Waveform and others
1 SUB-TINT
(I
2
C BUS
CONTROL)
1. Receive the “NTSC 3.58 Colour Bar” signal thru
AV in.
2. Connect the oscilloscope to TP853 (Pin (5) of
P882) BLUE-OUT.
»
Range : 100 mV/Div. (AC)
(Use Probe 10:1)
»
Sweep time : 10
µ
sec/Div.
3. Call the “SUB-TINT” mode in service mode.
Adjust the “SUB-TINT” bus data to obtain the
waveform shown as Fig. 9.
4. Clear the SERVICE mode.
PROTECTOR OPERATION CHECKING
NO. Adjustment part Adjusting procedure and conditions Waveform and others
1 BEAM
PROTECTOR 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.
* Select one of Q883/5/7 to do each
short test.
2 H, V
PROTECTOR 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.
A/V INPUT AND OUTPUT CHECKING
NO. Adjustment part Adjusting procedure and conditions Waveform and others
1 VIDEO AND
AUDIO OUTPUT
CHECK 1. Receive the “PAL Colour Bar” signal (100%
White Color Bar, Sound 400 Hz 100% Mod
C475.)
2. Terminate the Video output with a 75 ohm im-
pedance. Make sure the output is as specified
(1.0 Vp-p
±
3 dB).
3. Terminate the Audio output with a 10K ohm
impedance. Make sure the output is as speci-
fied (1.76 Vp-p
±
3 dB).
2 VIDEO AND
AUDIO INPUT
CHECK 1. Using the TV/AV key on the remote controller,
make sure that the modes change in order of
TV, AV1, AV2 & TV again and the video & audio
output are according to the input terminal for
each mode.
3 OTHER
PROTECTOR 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)
W
SAME LEVEL
Y Cy G Mg R B
Fig. 9