Troubleshooting
6. Troubleshooting
6-1 Checkpoints by Error Mode
■ Power LED: Check that the LED works when turning the Tact Switch ON/OFF
■ LED Indicators: See table 6-2-1 Basic Troubleshooting: LED Diagnosis on the Front Panel.
■ In case of a power failure or abnormal screen, check the following items.
1) Check that the power cord is correctly connected to electrical source equipment.
2) Check that the Tact Switch has been pressed.
3) Check that the signal cable is properly connected.
4) Check that channel setting has been set.
Samsung Electronics 6-1
Troubleshooting
6-2 Troubleshooting Procedures by Error Modes
6-2-1 Basic Troubleshooting: Diagnosis of LED on the Front Panel
◑ : Light is Blinking
○ : Light is Off
Power Description
○ This happens when the Tact Switch is not pressed or the power cord is disconnected.
If you press the power switch of the or the channel key on the remote control when in St-BY sta-
○→◑→● tus, the screen will be turned on.If the LED blinks and the screen is not displayed, check the
connection between the Power and the Main Board.
■ Troubleshooting Mechanism :
- The System Blcok has the last output terminal, TDA9377PS/N3, which shows the internal Test pattern.
- The Power Block supplies power to the Deflection Block
- The System Block receives all signal inputs, the signal-processed signal is sent to CRT Ass'y.
Deflection and focus are controlled by the Deflection Block
6-2 Samsung Electronics
Troubleshooting
6-3 Troubleshooting Procedures by ASS'Y
1. NO Power
2. NO Video
Samsung Electronics 6-3
Troubleshooting
3. NO Sound
4. Fly Back Lion Badness
CN603 CN602
CN701A
CN401
GT804,GT805
PD801S
6-4 Samsung Electronics
Troubleshooting
6-4 Troubleshooting by Blocks
6-4-1 Troubleshooting Main Board
1. Tuner Diagnosis
The RF / CTV signal is transmitted to the Tuner of the Main Board
If the signal is not received, check the following items
- Power supply: 5V, 33V
- Check for RF defects: Check the IF & CVBS output
- Check for AUDIO defect: Check the SIF Signal output
Samsung Electronics 6-5
Troubleshooting
2. Micom Diagnosis
- Power supply : 3.3V, 5V,8V
- Check for input defects : Y/C(CVBS), 480i Y/Pb/Pr signal
6-6 Samsung Electronics
Troubleshooting
3. External Input Diagnosis
This consists of AV1/2 and Component signal inputs as well as monitor output (Video, Audio).
The signals are sent to UOC and the selected signals are output.
If the signal input or output does not work, check the following items.
- Check for input defects: Check the Micom input pin.
- Check for output defects: Check JA701A (for RF/AV) or JA702(for comp)
Samsung Electronics 6-7
Troubleshooting
4. TDA7297SA (Audio Processor) Diagnosis
This receives the signal from the MICOM(TDA9377PS/N3) and outputs the signal in 10W + 10W sound.
- Power supply : 12.5V
- Check for input defects : AMP-R,AMP-L
- Check for output defects : L+, L-, R+,R-
6-8 Samsung Electronics
Troubleshooting
5. MSP3425G-B8(Audio Processor) Diagnosis
This receives the signal from the Audio Processor (TDA9377PS/N3) and outputs the signal in TDA9377PS/N3
- Power supply : 12.5V
- Check for input defects : B+8V, A+5V
- Check for output defects : DACM_R,DACM_L
Samsung Electronics 6-9
Troubleshooting
6-4-2 Troubleshooting Deflection Block
■ Countermeasures by Deflection Types
Countermeasures by Deflection Types
1. The screen is blank and only the relay repeats close and open when turning the power on.
This happens when the vertical voltage or vertical signal is not supplied, and because the Micom operates for 5 to 10 seconds and
then turns the power off by force as it cannot detect the vertical signal.
2. CHECK POINT
- Check that the vertical output voltage is measured in the FBT terminal.
VCC (+) : +16.5v
VCC (-) : -16.5V
If you cannot measure the output voltage, check that the collector voltage of the horizontal TR is 1360V.
If the voltage is measured, the problem is a defect in the FBT unit.
(When you don't have an oscilloscope, and you can hear the high-voltage sound, you can determine that the horizontal TR is
normal.)
Is the vertical input waveform output from the TDA9377PS/N3/A VDP Pin.
6-10 Samsung Electronics
