LG MW-30LZ10, Service Manual

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Symptom Cause Check Point
1) Check BD801, Q801, Q802, Q804
2) Check BD801, L801, L802, TH800, TH801
1) Check the second side parts and Pattern short
2) Check reverse input of PH801, D916, CR802
3) Check R941~R944 when the Pin Bias power no7. of
U902 is abnormal. (normal: 15V~25V)
- Replace U902(FAN7554) parts
- Check the error of Q804
4) Replace T803
1) Check the peripheral parts of 18V and Pattern short.
2) Check reverse input of D916(SB560)
3) No Input of L812 when both terminal voltage of C830
are low. (normal voltage: +24V)
- Replace U802(PQ1CG203) parts when there is no
error.
1) Check the peripheral parts of 5VS and Pattern short.
2) Check reverse input of D802, CR801
3) Check R937~R939 when the Pin Bias power no7. of
U903 is abnormal. (normal: 15V~25V)
- Replace U903(FAN7554) parts
- Check the error of Q802
4) Replace T802
1) Replace U901(MC33368D) when there is no error in
the peripheral parts.
- Check the error of Q801
2) Replace T801
1) Fuse open
2) Error of rectying circuit/EMI Filter
1) Short of output terminal
2) Input error of parts
3) Error of U902 and peripheral circuits.
4) Error of T803
1) Short of output terminal
2) Input error of parts
3) Error of U802 and peripheral circuits.
1) Short of output terminal
2) Input error of parts
3) Error of U903 and peripheral circuits.
4) Error of T802
1) Drop of output power due to the error
of PFC circuit.
2) Error of T801
1. No power from all outputs
2. No power from +24V/+12V
/+18V
3. No power from +18V
4. No power from +5VS
5. No power from +24V/+12V
/+18V in 110VAC Input
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