Part-1
- Before start troubleshoot, check the various connections first.
- Check and see if there is a burned or damaged cable.
- Check to see if there is disconnected or loose cable connection.
- Check to see if cables are connected according to connection diagram.
- Check the Power input to the Main Board.
- Check the voltage in and out between the SMPS <-->Main board, between SMPS <-->X,Y Main board and between Logic boards.
SYMPTOMS:
The LEDs on the front panel do not work when connecting the power cable. The SMPS relay does not work when connecting the power cable. The unit appears to be dead.
MAJOR CHECKLIST:
The SMPS relay or the LEDs on the front panel does not work when connecting the power cord if the cables are improperly connected or the Main Board or SMPS is not functioning. In this case check the following.
- Check the internal cable connection.
- Check the fuses.
- Check the output voltage of SMPS.
- Replace the Main Board.
SYMPTOM:
The SMPS relay is repeatedly turns ON and OFF.
In general the SMPS relay repeatedly turns ON and OFF by the protection function due to a defect on a board connected to SMPS.
MAJOR CHECKLIST:
Disconnect all cables from SMPS and operate the SMPS alone and check if the SMPS go on properly, and each output voltage is correct.
- If the symptom continues even when the SMPS is operated alone, it is faulty. Replace the SMPS.
- If the symptom is not observed when operating the SMPS alone, find any defective assemblies by connecting the cables one by one.
- NB: When sepaerating and connecting some cables, such as CN810,CN809,CN808,CN807, of the main SMPS, CN4701 of the X main Board, and CN5707 of the Y main board, a spark might be generated by the electric charge of the high-capacity capacitor. Therefore, wait some time after disconnecting the Main Power Cord from the unit.
SYMPTOM:
Audio is normal, but No Picture.
MAJOR CHECKLIST:
- This may happen when the Main Board is functioning, but the X,Y Main Board or T buffer board is not.
- Check the output voltage of the Main SMPS.
- This may happen when LDVS cable connecting the Main Board and the Logic Board is disconnected.
SYMPTOM:
Picture is normal, but there is no sound.
MAJOR CHECKLIST:
- When the speaker connectors are disconnected or damaged.
- When the sound processing part of the Main Board is not functioning.
- The speaker defect.
SYMPTOM:
A normal/cable network analog broadcast screen is blank or abnormal, while On Screen Display is OK.
MAJOR CHECKLIST:
- Check the antenna connection settings. [Air: NTSC / ATSC, Cable:NTSC].
- Check the CVBS cable connection.
- Check the Power Input of the main board.
SYMPTOM: A blank vertical cell [block] appears on the screen
Fault: Address buffer defect. Replace the corresponding upper/lower Buffers [E,F].
COF defect. [burned]; Replace the module.
A GREEN SCREEN APPEARS, WHEN TV IS TURNED ON.
The Scale is not resetting. Replace the Main Board.
ON THE SCREEN DISPLAY BOX IS PRESENT, BUT NO TEXT
Incorrect Program Version. Check the version of each program. Replace the main board.
A BLANK UPPER OR LOWER BLOCK APPEARS ON THE SCREEN
Upper or Lower Y buffer defect.
Replace the corresponding Upper/lower buffers [E,F]
EITHER THE MAIN OR SUB PICTURE DOES NO APPEAR
Replace the main board.
A VERTICAL GREEN LINE APPEARS ON THE SCREEN
The SMPS voltage is incorrect. Adjust the SMPS voltage according to the voltage printed on the module label.
DIM SCREEN / BLURRED IN RED
X-Main board defect. Replace X-main board.
A BLACK SCREEN APPEARS
Replace 'Y" Main Board
continued: in part-2
