![Sharp 21XF30 Service Manual Download Page 20](http://html.mh-extra.com/html/sharp/21xf30/21xf30_service-manual_373513020.webp)
20
21XF30
21XF50
20-1
20-2
TROUBLE SHOOTING TABLE
NO RASTER
Blown out.
Replace the fuse.
Check IC701, D701 and
C707.
The fuse is again blown out.
Does horizontal circuit
oscillate ?
D1001 (Power LED Red)
turns on or turns ON/OFF.
Check T701 pin (7) voltage
(Approx. 310V at 220V AC)
Check F701.
Check Secondary Main+B
(Approx. 120V)
Check CRT connector K1-
K5 bias.
Check IC605, IC751 and
IC801.
Check
C878.
Check
IC801.
Checking the
protector circuit.
Check R615.
D1001 (Power LED) turns
on and off.
See many often D1001
flash in red.
This indicates which IC to
check up.
D1001 (Power LED Green)
turns on.
Check D758, IC702, IC753
and D762.
Check R701, R707 and
D709.
LIGHTS UP
TURN OFF
TV PROCESSOR
(IC801)
EEPROM
(IC1003)
AV SWITCH
(IC401)
SOUND PROCESSOR
(IC305)
NICAM/A2 DECODER
(IC2300)
TUNER
(TU201)
TROUBLE SHOOTING TABLE
(Continued)
NO PICTURE, NO SOUND
Does noise signal appear at
pins (3) and (22) of IC305 ?
NO SOUND
No snow noise.
Does noise or signal appear at pin (40)
of IC801 ?
Noise increases but no signal is
received.
Check the tuner supply voltage LB and
HB must be approx. 5V. BT must be
approx. 32V. and CH preset data check.
Check the tuner AGC at
TP201.
Does noise or
signal appear at
pin (38) of IC801 ?
Check IC801 and
its related circuit.
Check IC401 and
related circuit.
Check pin (1) of
SF201, Tuner and
related circuit.
Check pin (37)of
IC801 and related
circuit.
Check pin (27) of
IC801, Tuner and
related circuit.
Check pin(38) of
IC801.
Does the noise level increase at max.
Contrast, Brightness and Sound controls ?
CIRCUITS TO BE CHECKED:
»
Tuner.
»
PIF.
»
Automatic Gain Control.
»
(5V), (32V) Power Source.
CIRCUITS TO BE CHECKED:
»
Sound Detector Circuit.
»
Sound Switch and Att.
Control.
»
Audio Output Circuit.
Does signal appear at pins
(2) and (5) of IC302 ?
Check IC401 and its peripheral
circuit.
Check Speaker.
Does noise or
signal appear at
pin (23) and (24)
of IC801 ?
Check IC302 and
peripheral circuit.
Summary of Contents for 21XF30
Page 23: ...23 21XF30 21XF50 23 1 23 2 M E M O ...
Page 24: ...24 21XF30 21XF50 CHASSIS LAYOUT 21XF30 ...
Page 25: ...25 21XF30 21XF50 CHASSIS LAYOUT 21XF50 ...
Page 26: ...26 21XF30 21XF50 BLOCK DIAGRAMS MAIN 1 UNIT 21XF30 ...
Page 27: ...27 21XF30 21XF50 ...
Page 28: ...28 21XF30 21XF50 MAIN 1 UNIT 21XF50 ...
Page 29: ...29 21XF30 21XF50 ...
Page 33: ...33 21XF30 21XF50 10 11 12 13 14 15 16 17 18 19 ...
Page 34: ...34 21XF30 21XF50 A B C D E F G H I J 1 2 3 4 5 6 7 8 9 10 MAIN UNIT 1 21XF50 ...
Page 35: ...35 21XF30 21XF50 10 11 12 13 14 15 16 17 18 19 ...
Page 36: ...36 21XF30 21XF50 A B C D E F G H I J 1 2 3 4 5 6 7 8 9 10 MAIN UNIT 2 21XF30 ...
Page 37: ...37 21XF30 21XF50 MAIN UNIT 2 21XF50 A B C D E F G H I J 1 2 3 4 5 6 7 8 9 10 ...
Page 38: ...38 21XF30 21XF50 CRT UNIT 21XF30 A B C D E F G H I J 1 2 3 4 5 6 7 8 9 10 CRT UNIT 21XF50 ...
Page 39: ...39 21XF30 21XF50 MONO BILLINGUAL UNIT 21XF30 A B C D E F G H I J 1 2 3 4 5 6 7 8 9 10 ...
Page 40: ...40 21XF30 21XF50 A B C D E F G H I J 1 2 3 4 5 6 7 8 9 10 NICAM A2 UNIT 21XF50 ...
Page 41: ...41 21XF30 21XF50 10 11 12 13 14 15 16 17 18 19 ...
Page 43: ...43 21XF30 21XF50 10 11 12 13 14 15 16 17 18 19 ...
Page 44: ...44 21XF30 21XF50 A B C D E F G H I J 1 2 3 4 5 6 7 8 9 10 PWB A MAIN Unit Chip Parts Side ...
Page 45: ...45 21XF30 21XF50 10 11 12 13 14 15 16 17 18 19 ...
Page 47: ...47 21XF30 21XF50 PWB D MONO BILLINGUAL Unit Component Side A B C D E F G H I J 1 2 3 4 5 ...
Page 57: ...Ref No Part No Description Code Ref No Part No Description Code 57 21XF30 21XF50 ...