Sharp DV-550U, Руководство по обслуживанию

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DV-550U
11-1
11. TROUBLESHOOTING
FLOW CHART NO.1 POWER TROUBLESHOOTING(1)
No power.
Unplug the AC power cord. See FLOW CHART NO.2 POWER TROUBLE-
Replug it a few minutes later. SHOOTING(2)
No No
Is the fuse good? Replace fuse.
Yes No
Is AT 5V voltage line normal?
Check primary circuit,D9007,L9001,C9019,C9014
and C9013.
Yes
Are AT 8V,AT 12V,AT -30V and filament voltage
lines normal? No Check each recifier circuits and short-circuit of
secondary circuit.
FLOW CHART NO.2 POWER TROUBLESHOOTING(2)
In case of Fuse(F9001) blown out.
Replace F9001,Q9007,Q9010 and D9020, check
D9016 as a result of check, if poor, replace at the
same time. Check short-circuit or leak of D9005 thru to D9008
and secondary circuit.
FLOW CHART NO.3 POWER TROUBLESHOOTING(3)
In case of abnormal noise(sound).
Check D9024,D9005,D9006,D9007 and D9008.
FLOW CHART NO.4 POWER TROUBLESHOOTING(4)
In case of output voltage at low level.
No
Check the D9014,Q9006 and Q9009. Replace D9014,Q9006 and Q9009.
Yes No
Check D9020. Replace D9020.
No
Check short-circuit or leak of T901. Replace T9001.
Yes
Check primary circuit,Q9007,Q9010,C9023,C9024,
C9027,D9011 and D9014.
FLOW CHART NO.5 DISPLAY TROUBLESHOOTING
The fluorescent display tube fails light up.
No
Is the supply voltage of 5V fed to pin(18) of
Check AT 5V line.
IC5001?
Yes
Is the supply negative voltage of -30V fed to pin
(16) of IC5001? No Check negative voltage line (AT -30V) and power
circuit.
Yes
No
Is there about 4MHz oscillation at pins(19) and
(20) of IC5001?
Check FL5001 and IC5001.
Yes
Is filament voltage applied between (1)/(2) and
(61)/(62) of the fliorescent display tube?
No Check power circuit and peripheral circuit of
D5001.
Also negative voltage applied between these pins
and ground.
Yes No
Dose the flourescent display tube function? Check for cracks on the flourescent display tube.
Yes
Replace IC5001.
Yes
Check D8022 and R8030.