Sharp XG-MB67X, Service Manual

Page: 33 / 128

XG-MB67X
8 – 5
Power supply PWB-
check
Is 6 V applied to pins
(7) and (8) of the con-
nector P704? NO
YES
Is 13 V applied to
pins (3) and (4) of the
connector P704? NO Check peripheral cir-
cuits of IC703.
YES
Does the lamp turn
on? NO Are connectors P704
and CN901 fully
inserted? NO Securely insert the con-
nectors.
YES YES
Check the main
PWB. Is DC voltage of 380 V
applied to both ends
of C704? NO Is pin (11) of the connec-
tor P704 at "H"? NO Check the main
PWB.
YES
YES
Check peripheral circuits
of IC902.
Is R766 in the OPEN
status? NO Is LAMP-EN/SYNC sig-
nal properly sent to pin
(14) of the connector
P704? (Refer to the
waveform chart .)
NO Check the main
PWB.
YES YES
Check circuits R766
and after or replace
R766. Are GATE waveforms of
Q901 and Q903 appro-
priate? (See waveform
diagram .)
NO Check the Power
PWB.
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1
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