Troubleshooting Guide - Sharp OPTONICA SM-3000H Service Manual

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ALL OPERATIONAL MODES (1)
NO SOUND AC POWER OK
ALL MODES
:
NORMAL AT DC.
DETECTED
DEFECTIVE DC
DETECTED
NO AC POWER,
PILOT INDICATOR
IS OFF
POWER INDICA-
TOR IS ON, BUT
NO SOUND
WEAK SOUND
ALL MODES
NO SOUND
AT ONE
MODE
AT AUX, TUNER
AT PHONO-1 OR
PHONO-2
AT TAPE MODE
TROUBLE SHOOTING GUIDE
PROBABLE CAUSE
BROKEN OR SHORTED SPEAKER
CORD NETWORK OR VOICE COIL
NOT OPERATE RELAY
DEFECTIVE MAIN SUPPLY AMPLIFIER
NO POWER AT WALL SOCKET
|
DEFECTIVE ON-OFF SWITCH OR
LINE CORD
LOOSE AC PLUG CONTACT
BLOWN FUSE
SHORTED POWER TRANSFORMER
SHORTED CAPACITOR
SHORTED POWER TRANSISTOR
SHORTED POWER SUPPLY CIRCUIT
OF POWER AMPLIFIER
BROKEN PRIMARY WINDING OF
POWER TRANSFORMER
DEFECTIVE POWER SUPPLY CIR-
CUIT
BLOWN FUSE
DEFECTIVE OR SHORTED POWER
TRANSISTOR
DEFECTIVE OR SHORTED DEVICE
AT OUTPUT
DEFECTIVE AUDIO AMPLIFIER
DEFECTIVE TRANSISTOR
LOW AC SUPPLY VOLTAGE
DEFECTIVE POWER CIRCUIT
DEFECTIVE FUNCTION SWITCH OR
SOCKET
DEFECTIVE EQUALIZER AMPLIFIER
DEFECTIVE FUNCTION SWITCH, IMP
SWITCH, ATT SWITCH OR SOCKET
DEFECTIVE TAPE SWITCH OR
SOCKET
WHAT TO DO OR CHECK POINT
CHECK CONTINUITY OF SPEAKER
CORD, AND VOICE COIL
REPAIR BROKEN CORD OR RE-
PLACE SPEAKER
CHECK RELAY, 0801 ~ Q806 AND
VOLTAGE AT Q806 (EMITTER)
REFER TO NEXT
IF THE FUSE BLOWS AS SOON AS
IT IS REPLACED
T901
C902, C901
Q901 ~ Q904
CHECK CONTINUITY BETWEEN THE
COLLECTOR AND EMITTER, IF IT IS
0 OHM OR CLOSE TO O OHM, IT IS
DEFECTIVE
CHECK CONTINUITY OF POWER
SUPPLY CIRCUIT
CHECK CONTINUITY OF TRANS-
FORMER
DIVERGENCE OF VOLTAGE SPECI-
FIED IN "SCHEMATIC DIAGRAM"
IF THE FUSE BLOWS AS SOON AS
IT 1S REPLACED
Q901 ~ 0904
SPEAKER SYSTEM, HEADPHONE
DIVERGENCE OF VOLTAGE SPECI-
FIED IN "SCHEMATIC DIAGRAM"
Q501A (B) ~ Q511A (B)
CHECK THE VOLTAGE SELECTOR
(REAR)
DIVERGENCE OF VOLTAGE SPECI-
FIED IN "SCHEMATIC DIAGRAM"
SW301A, B, C, SO904A (B), SO905A
(B)
DIVERGENCE OF VOLTAGE SPECI-
FIED IN "SCHEMATIC DIAGRAM"
SW301A, B, C, SW903, SW904, SO906A
(B), SO907A (B)
SW408A (B), SO902A (B), SO903A (B)
[ALL OPERATIONAL MODES (2)]
[_symerom _|
| | SYMPTOM |
REPLACE SPEAK-
ER AND OK
ee -—- Oro
DISTORTION
IN ALL
MODES OF
OPERATION
ONE CHANNEL IS
OK, OTHER |S
DISTORTED
HIGH LEVEL OF
RIPPLE IN DC
SOURCE
HUM IN ALL
MODES
RIPPLE IN POWER
SUPPLY CIRCUIT
OF PREAMPLIFIER
LOUDNESS
CONTOUR
SWITCH
DOES NOT
WORK AT
ALL
CONTROL
DOES NOT
WORK
BASS CONTROL
TREBLE CONTROL
BALANCE CONTROL
PROBABLE CAUSE WHAT TO DO OR CHECK POINT
REPLACE SPEAKER DEFECTIVE VOICE COIL, CONE OR
DAMPER OF SPEAKER
INSUFFICIENT VOLTAGE OF POWER + VOLTAGES NOT AS SPECIFIED
CIRCUIT
DEFECTIVE AUDIO FREQUENCY
CIRCUIT
AGING OR WEAK IC OR TRANSISTOR | 1C401, Q501A (B) ~ Q511A (B),
Q901 ~ 0904
OPEN OR SHORTS IN NEGATIVE
FEEDBACK CIRCUIT
DEFECTIVE CONSTANT VOLTAGE
CIRCUIT
DEFECTIVE CONSTANT VOLTAGE C903, C904
CIRCUIT
SHORT CIRCUIT OF EARTH OF
POWER AMPLIFIER OR OTHER
AUDIO UNIT TO CHASSIS, ESPE-
CIALLY HEADPHONE JACK TO
CHASSIS
VOLUME CONTROL IS IN OVER
REVOLUTION
DEFECTIVE LOUDNESS CONTOUR
SW404 SWITCH OR CIRCUIT
R520A (B), R517A (B), C511A (B),
TONE CtRCUIT
L801, L802, ZD801, ZD802
AF UNIT TO CHASSIS, J901 TO
CHASSIS
NORMAL
SW404, C401 ~ C404, R407 ~ R410
DEFECTIVE VR303A (B) OR CIRCUIT
DEFECTIVE VR304A (B) OR CIRCUIT
DEFECTIVE VR301A (B) OR CIRCUIT