SAMSUNG CL21C650MLMXZD TV SERVICE MODE AND ADJUSTMENTS, FAULT AND RECTIFICATION, SCHEMATIC DIAGRAM

Samsung CL21C650 CRT TV Service mode and adjustments, fault symptoms and repair, schematic diagram

Troubleshooting by the Checksum

Diagnosis of trouble by the checksum is neither reliable nor convenient.
You can only use the checksum of the current direct-view TV to determine whether the software is corrupted or not.
The Checksum value is determined according to the version of the software loaded on the set.
Therefore, you can determine whether the software has been properly downloaded, if you know the correct checksum for that version of the software.
You can check the checksum according in the following order.
Factory Mode → Checksum → Enter → Output Checksum (e.g. 0xab2b)

Checksum Examples
T-SIXPEANM -1000.0 Checksum = XXXX

General Adjustment
In general, a color TV can provide ideal visual quality by adjusting the basic settings such as the vertical size, horizontal size, focus, etc.
Display a black and white picture on the screen to check if the picture is clearly displayed.
If there are some ‘spotted’ points on the screen when displaying a black and white picture, degauss the screen using the degauss coil. If the spotted points remain, re-adjust the purity and the convergence.
This completes the basic performance examination.

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

Adjusting the Picture Size
Since the KSBA chassis includes a deflection adjustment of the Factory Data, adjustments must be performed according to the following procedures when replacing the Main Board.

1. Display the Lion pattern.
2. Press “Power Off → Info → Menu → Mute → Power On” using the remote control and enter Factory Mode.

3. Enter Deflection Mode.
4. Adjust the V-AMP, V-SHIFT, H-EW and H-SHIFT items so that the width becomes 92 and the height becomes 92.

Adjusting the Picture Straight Lines
Display the Cross Hatch pattern.

Adjusting the Focus

,1. Display the Cross Hatch pattern.
2. Set the Screen Adjustment to “OK”.
3. Turn the Focus VR so that the horizontal and vertical lines are clearly displayed.
4. Check the Focus for the entire screen and adjust the Focus VR if necessary.

Adjusting the Screen Voltage
1. Select: Power OFF >  Info >  Menu >  Mute >  POWER ON
2. Initialize all settings to the values appropriate to the corresponding model make sure the video adjust 1 is the factory date.

3. Select: Mute, and get into the G2 adjust Toshiba pattern.

4. First check IBRM in “G2 Adjust” of Factory and adjust Screen VR until “Screen Adjust : OK”

Adjusting the White Balance

1. Select: Power OFF >  Info >  Menu >  Mute >  POWER ON
2. Initialize all settings to the values appropriate to the corresponding model.
3. Display the Toshiba pattern and adjust the White Balance using CA100 with the coordinates of the corresponding model

4. Enter Video Adjust1 of Service Mode. Adjust Low/Light.
- Adjust Sub Bright to set Y.
- Adjust B Cutoff to set y.
- Adjust R Cutoff to set x.
5. Enter Video Adjust1 of Service Mode. Adjust High/Light.
- Adjust Sub Contrast to set Y.
- Adjust B Drive to set y.
- Adjust R Drive to set x.
6. Check Low/Light and readjust it if its value has been changed.
7. If you have readjusted Low/Light, readjust High/Light until the two values are identical to the coordinates of the corresponding model.

Check List for the Screen Voltage and White Balance Adjustment
1. The Screen Voltage and White Balance are connected to each other, and both of them have to be configured to the correct values.
2. Adjust the White Balance after the Screen Voltage was adjusted, and check if the Screen Voltage is normal after adjusting the White Balance.
3. If the White Balance is readjusted, check the Screen Voltage again.
4. When the adjustment is finished, check the following checklist.
- If there is a spot on the screen when turning the TV set off/on, adjust the Screen Voltage again.
- If there is a ghost line on the screen, adjust the Screen Voltage again.

Block and Schematic diagrams

     Service help - Common faults

•Full screen with retrace lines – D209

•Crooked line in the middle of the screen – faulty vertical output IC LA78045.

•Vertical closing at the bottom – Zener diode ZD302, 24Volt supply, ZD303, 39Volt supply

•Closed vertical from the middle to the top – faulty vertical output IC LA78045

•High source voltage – horizontal drive transformer T401 or 1402.

•Dark image without video – Zener diode ZD210 - 9.1V

•LED flashes 5 times after switched off – filter capacitor C822A – 100MFD 160V

•Vertical fold at the top – DZ302, DZ303 short, DZ306 should be checked for short.

•Horizontal output transistor heats up very fast Q401 – C415. The 27K resistor connected to it measures 23K.

•Reduced image size, horizontal output transistor heats up too – C407 250nf 250V open. Replace the same.

•Blue screen with retrace lines = check the 15K resistor at the tube plate.

•Dark image when increasing the screen appears reduced image, with retrace lines and a horoxontal bar in the middle of the screen – 254J250V CR407S burned out capacitor.

•Picture without sound – Audio output IC faulty.

•Image behind – Memory fault.  Change the memory.

•No vertical deflection – LA78045 faulty or loose solder terminals.

`LED light turns ON and then turns OFF, protection triggers, buzzing sound as if the LOT is faulty. Bit not. – Zener 805, the transistor 806, transistor 805.

•Excess width – capacitor at the horizontal circuit. In this chassis, it has changed, but no number on the board.

•Image at the middle of the screen only, closed at sides – L408.

•TV On and the source goes up and enter protection, after horizontal output transistor TT2206 changed – Horizontal driver with open coil.

•Frame reduced. Horizontal closes. Fold in the middle of the screen – CR407 254J 250V, R426 2K2 1W.

•Screen with waves and the sourse voltage goes low and high – primary source section should be checked.

•Horizontal output transistor burns frequently – CR402S, C402 15nf.

•Set does not starts normally when LED turns OFF – transistor Q401 J6810 open.

•Vertical distortion at the top [closed], image present from the middle to the bottom – IC LA78045, D303.

•Source voltage does not work – 33V DZ12 leaky.

•Folds in the middle of the screen, horizontal closes – CR407s near the Flyback transformer.

•Lines on the top of the screen – D303.

•Vertical closed from the top to the middle of the screen – opened diode D303.

•Horizontal output transistor burns out – C415 27K short.