LG HT903WA Service Manual page 21

7. AUDIO µ-COM Circuit(DVD & AMP)
Power On.
YES
Does
CD/DVD appear at
FLD?
YES
Does
Loading appear
at FLD?
YES
Does
NO
no Disc or Time
appear at FLD?
YES
Check
if DVD an audio
micom insert is
OK.
YES
NO
Check Power.
YES
Check DVD Module.
YES
Check SMPS.
LGE Internal Use Only
NO
Does
NO
it appear DVD Error
at FLD?
YES
Check
power part of Main
B/D.
YES
Check
oscillator o
X101.
YES
Check
if IC101 Pin5
is high.
YES
Check
if IC101 Pin9,36,59
are high(5V).
YES
Check
if IC101 Pin44
is high.
YES
Replace IC101.
Does AV1,
TV AUDIO, AV1 OPT and
FM 87.5 appear
at FLD.
NO
NO
NO
Refer to SMPS.
NO
Refer to oscillator cir-
cuit.
NO
Check IC101 reset
waveform.
NO
Check 5V line.
NO
Check power section
circuit.
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YES
OK
Only for training and service purposes