SAMSUNG CL21K40 - CRT TV - SERVICE MODE - CIRCUIT DIAGRAM - TROUBLESHOOTING

SAMSUNG CL21K40 - CRT TV - SERVICE MODE - CIRCUIT DIAGRAM - TROUBLESHOOTING

Schematic - Service Mode - Default Data values - Samsung 21 inch CRT TV

TDA9377PS/N3/A: CVBS, Video and Sound Signal Processing, Controls the operation of the overall main board.  TDA7297SA : Sound Signal Amplify.  KA5Q0765RTH-YDTU : Power Supply TR.  TUNER-F/S;TDQ-6F/13F2S(tuner) : RF signal processing , Output IF signal. System : SECAM/NTSC4.43/NTSC3.58

 UOC TDA9377PS/N3/A. It contains the entire IF, audio, video, display and deflection processing for 4:3 and 16:9 50/60Hz mono and stereo TV sets. The integrated microcontroller is supported by a powerful OSD generator with integrated Teletext and CC acquisition
 ST2001HI: Imputed H-DRIVE signal which comes from TDA9377PS/N3/A. It amplifies the H-DRIVE then output to Deflection Yoke.
 LA78045: Inputted VDP signal which comes from TDA9377PS/N3/A. It amplifies the VDP then output to Deflection Yoke.
 TDA7297SA:It is a dual channel audio amplifier. The two audio signals L and R input to it and are amplified, then output to speaker.
 6107:It includes three video output amplifiers and is intended to drive the three cathodes of a color CRT directly. The output R,G,B signals will connect to the CRT socket pins directly.
 EEPROM: As a extended ROM of TVT. It contains some data which is used to program executing.
 KA5Q0765RTH:SMPS control HIC. Provide switching signal in order to control the trans working.
 TDQ-6F/13F2S(TUNER):Receives the RF signal and output a fixed IF to Micom.
 Micom Block consists of five aspects as: Video & Sound IF Processor, Video Processor, Display and Deflection Processor and Controller, OSD,Text Processing.
 TUNER-F/S;TDQ-6F/13F2S(tuner) : RF signal processing , Output IF signal.

 This chassis is a classic direct view type TV, the Ass'y is different function parts are in one PCB.
 The Power Block is same as the existing model KS9A.
 The AV signal is input through the AV port and Side AV port of the System Block.
 The signals were processed by MICOM, then output.
 This chassis's MICOM is same as KS9A, it use UOC CHIP.
 The external port be consists of AV input and output, each of them has three channels, Audio are White and Red, Video is Yellow Video(Yellow).

DISASSEMBLE CRT BASE CARD

Separate the wires from the FBT of the Main Board and the CRT Ass'y.

To separate the red wires and white wires, pull the wires while pressing the push-type clip at the connector.

Take care when separating the wires because pulling the wires by force may damage the socket. In addition, separate the wires on a flat and clean surface so as to prevent scratching of the material and the PCB.

CRT BASE CARD SCHEMATIC

AUDIO OUTPUT - SCHEMATIC

MICOM SCHEMATIC

SMPS – HORIZONTAL AND VERTICAL DRIVE

MAIN BOARD AND CONNECTORS

 CN602 : This is a 4 pin port connected to the SPEAKER port, which delivers the signal from the AMP to the speakers.
 CN603 : This is a 5 pin port connected to the AV ASSY, which delivers the signal to the headphone.
 CN501A : This is a 9 pin port connected to the CRT ASSY, which outputs the R/G/B signal to the CRT ASS'Y for display and Power signals to the CRT DRIVE.
 CN701A : This is 8 pin port connected to the AV ASSY, which receives AV2 external input.
 CN401 : This is a 4 pin port connected to the DY, and supplies voltage for Deflection.
 GT804,GT805 : This is a port connected to the D-Coil surrounding the CRT.
 PD801S : This is a 3 pin port connected to the AC power cable. It is connected to the power cable socket.

Troubleshooting Deflection Block

Countermeasures by Deflection Types
 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.
 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.

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

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-

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)

Troubleshooting Main Board
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.

Basic Troubleshooting: Diagnosis of LED on the Front Panel

Light is Blinking
Light is Off

If you press the power switch of the or the channel key on the remote control when in St-BY status, 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.

When replacing the Main Board: Focus adjustment, screen voltage setting and W/B adjustment are all required.
When replacing the CRT Ass'y : No adjustments required.

To enter Service Mode, press the keys on the remote control according to the following sequence. (in Stand-by status)

Info → Menu → MUTE→ power On.

When failing to enter Service Mode, repeat the procedure above.

▲ / ▼  Move the cursor to select an item.

◀ / ▶  Adjust the selected configuration value.

DEFAULT DATA VALUES

Since the KS9C chassis has the deflection settings data within the Factory Data, the picture size has to be adjusted when replacing Main Board.

Adjusting the Screen Voltage
1. Select "Power Off > MUTE > 1 > 8 > 2 > Power On " to enter Service Mode.
2. Turn to Toshiba pattern
3. Use remocon come into " G2 Adjust" mode by hand or automatically.
4. Turn Screen VR of FBT and confirm the characters displayed changes to GREEN.