Sharp VC-S2000HM, Service Manual, Page: 37 / 123

37
VC-S2000HM
FLOW CHART NO.1 POWER TROUBLESHOOTING(1)
No power
Unplug the AC power cord. Replug it a few minutes later.
See FLOW CHART NO.2 POWER TROUBLESHOOTING(2)
YES
YES
YES YES
YES
NO NO
NO
NO
NO
Is the fuse good?
Replace fuse.
Is AT 5V voltage line normal?
Check primary circuit.
Are AT 37V , AT 12V, AT -28V and filament voltage lines normal?
Check each rectifier circuits and short-circuit of secondary circuit.
Is "H" level applied at pin(1) of IC701?
Check peripheral circuits Q9603 and P-FAIL (L) signal line etc.
Check system control circuit(IC701). 7. ELECTRICAL
TROUBLESHOOTING
FLOW CHART NO.3 POWER TROUBLESHOOTING(3)
In case of abnormal noise(sound)
Check D9601, D9602, D9603, D9604 and D9606.
The D9601, D9602, D9603, D9604 and D9606 as a result of check, if poor the replace.
NO
FLOW CHART NO.2 POWER TROUBLESHOOTING(2)
In case of Fuse(F901) blown out.
Replace F901, Q901 and R904, check D910, D911, D912 and D913 as a result of check, if poor, replace at the same time.
Check short-circuit or leak of D9601, D9602, D9603, D9604, D9606, D9607 and secondary circuit.
FLOW CHART NO.5 TIMER TROUBLESHOOTING (1)
The flourescent display tube fails light up.
Is the supply voltage of 5V fed to pin(18) of IC801?
Check STBY 5V line.
Is the supply negative voltage of -28V fed to pin(16) of IC801?
Check negative voltage line(STBY -28V) and power circuit.
Is the filament voltage applied between (1) and (62) of the fluorescent display tube? Also negative voltage applied between these pins and GND.
Check power circuit and peripheral circuit of D9701.
Does the fluorescent display tube function?
Replace IC801.
Check for cracks on the fluorescent display tube.
YES YES YES
YES
NO
NO
NO
NO
YES
YES
YES
NO
NO NO
FLOW CHART NO.4 POWER TROUBLESHOOTING(4)
In case of output voltage at low level.
Check peripheral circuits IC9601, C9613, R9608, R9609, R9610 and R9611.
The IC901, IC9601, C9613, R9608, R9609, R9610 and R9611 as a result of check, if poor the replace.
Check IC901.
Replace IC901.
Check short-circuit or leak of T901.
Replace T901.
Check primary circuit and peripheral circuit of Q901 and Q902.