Daewoo DLT - 42G1LTBD, Service Manual

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Trouble Shooting
5-4. Facts you must know when trouble diagnosing or repairing.
A. Trouble diagnosing and repairing of set mean find out which PCBs or blocks are not
working and replace them with new PCBs. Repairing the broken PCBs are not
necessary. Keep the broken PCBs and return them to service center or R&D center.
B. This TROUBLE DIAGNOSIS list only contains representative and simple PCB
trouble diagnosis and Module Exchange method. Therefore, if you find Sets that are
difficult to diagnosis or to repair, contact R&D center.
C. Basic TROUBLE DIAGNOSIS process.
Note : HEATRUN is conducted for at least 30 minutes with input TEST PATTERN
FULL WHITE
D. Required equipments for trouble diagnosis
-Digital Multimeter
User Mode: measure DC VOLTAGE, DIODE VOLTAGE, SHORT/OPEN TEST
-Screwdriver or electric screwdriver, plastic adjusting tool
-Oscilloscope (for detailed examination only)
E. Each BLOCK operations explained in this manual include oscilloscope waveforms,
but these are for reference only and utilizing them to repair PCBs is not necessary.
F. Before replacing PCBs, you MUST turn off the AC switch.
G. After replacing POWER, MAIN and SUB PCB, extra adjustment might be needed.
H. After the set is repaired, leave BACK COVER open for followings. Run HEATRUN for
at least 30 minutes by displaying TEST PATTERN (Full White) of SERVICE MODE.
Check the screen conditions and basic functions.(Remote Controller operation etc.)
J. After BACK COVER is closed, redo HEATRUN for at least one hour with Full White
input using TEST PATTERN of SERVICE MODE. Check the screen conditions and
basic functions.
Check problem
Symptoms
Open Back cover Trouble Diagnosis
& replace broken
Heat Run and
Full function test
Repair complete Adjust new PCB
module