Samsung HLR5078WX, Service Manual

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Troubleshooting
Samsung Electronics 6-5
6-1-1 Video Circuit Error Checking
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Basics:
- The DDP1011 on the DMD board has a feature to display internal test patterns.
- DNle, which is an end port in the digital board, has a feature to display internal test patterns.
- The analog board sends signals to ADV7401 on the digital board.
- The analog board is the first output and the digital board is the second one, followed by DMD, which is the final one.
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Diagnosis By Module
1. Access Service Mode
(In Standby mode, press "Mute", "1", "8", "2" and "Power" to turn the screen on and enter service mode)
2. Check if there is an error in the DMD board
DDP1011
→
TEST PATTERN
→
Press the right arrow key:
Options of FULL WHITE, BLACK, RED, GREEN and BLUE PATTERN are displayed on the screen.
If "Pattern" does not appear, this is a DMD board error.
3. Check if there is an error in the digital board before the DMD.
When the DMD board has been determined to be error free based on the test patterns:
FACTORY MODE
→
DNIe
→
TEST PATTERN normal display: no error in the digital board.
If "Pattern" does not appear, you have to check a Analog board first, and check a DMD Board second, next check a Digital
Board.
4. Check if there is an error in the Analog Board.
Check for a power signal from the analog to the digital boards. (See the circuit diagram below).