Hitachi DV-PF7E Service Manual page 30

FLOW CHART NO.11
DVD-P-ON+12V is not outputted. (AL+12V is outputted normally.)
Is the "L" pulse (approximately 0V) outputted to
the collector of Q1054?
Replace Q1053.
FLOW CHART NO.12
DVD-P-ON+5V is not outputted. (AL+5V is outputted normally.)
Is the "H" pulse (approximately 6V) inputted to
the base of Q1055?
Replace Q1055.
FLOW CHART NO.13
DVD-P-ON+3.3V is not outputted. (EV+3.3V is outputted normally.)
Is the "H" pulse (approximately 4V) inputted to
the base of Q1052?
Replace Q1052.
FLOW CHART NO.14
The fluorescent display tube does not light up.
Is 3.3V voltage supplied to Pin(6, 24) of IC612?
Is approximately -24V to -28V voltage supplied to
Pin(15) of IC612?
Is there approximately 500kHz oscillation to
Pin(26) of IC612?
Are the filament voltage applied between (1, 2)
and (29, 30) of the fluorescent display tube?
Also negative voltage applied between these pins
and GND?
Replace the fluorescent display tube (IC611).
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Check Q1054 and PWRCON line, and service it if
defective.
No
See FLOW CHART NO.11. <DVD-P-ON+12V is
not outputted. >
No
See FLOW CHART NO.11. <DVD-P-ON+12V is
not outputted. >
No
Check the EV+3.3V line and service it if defective.
No
Check the -FL line and service it if defective.
No
Check R618, IC612 and their periphery, and
service it if defective.
No Check the power circuit, D1016, D1017,
R1040, C1018 and their periphery, and
service it if defective.
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