Daewoo DQD-2100D, Service Manual

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26
TROUBLESHOOTING
1. POWER circuit
✓
Caution
You must use insulated trance during the first part test of POWER circuit.
No POWER
POWER cord/fuse is OK?
Voltage connected at D801?
Voltage connected at L804?
Switching wave at T801 pin
#6,7,8?
D821, D822, D823, D824, D825,
D826, D827 are OK?
Exchange POWER code/fuse
Check L801,L802
Check Q801
Exchange inferior ITEM
Check IC801, IC802
NO
YES
YES
YES
YES
NO
NO
NO
NO
+5V obtained at IC802 base and
+2.5V obtained at emitter?
YES
+12V obtained at Q823 drain and +5V
obtained at Q824 drain?
Check D803,D804,D805
+3.3V obtained at Q821, Q822 base when
POWER OFF "H"?
YES
NO
Check Q823, Q824, Q821, Q822 and
neighboring ITEM
Check L812, L822
NO
Check DVD PCB
NO