SAMSUNG CT2088BL6X-XAP, CT1488BL6X-XAP Service Manual

SAMSUNG

COLOR TELEVISION RECEIVER

Chassis : K15A (H) Model: CT2088BL6X/XAP

CT1488BL6X/XAP

COLOR TELEVISION RECEIVER CONTENTS

Precautions

Specifications

Alignment and Adjustments

Troubleshooting

Exploded Views and Parts List

Electrical Parts List

Block Diagram

Wiring Diagrams

Schematic Diagrams

ELECTRONICS

Printed in Korea

3K15A-8801

Alignment and Adjustments

Samsung Electronics 3-1

3. Alignment and Adjustments

3-1 Service Mode Adjustments

3-1-1 Service Mode Menus

Since there are no VRs in the K15A chassis, all adjustments after parts replacement must be done in the Service Mode. Service Mode adjustments are necessary when either the EEPROM (IC902) or the CRT is replaced.

3-1-2 Entering the Service Mode

Press the following transmitter keys while in STAND-BY mode:

MUTE—>1—>8—>2—>POWER “Factory Mode Menu” is displayed

Enter Service Mode using the Volume

+,- keys. Service Mode Menu:

Return to the Service mode by pressing MENU.

Change the data with “Volume +, - “ keys.

Return to the Factory mode via the MENU key.

Press POWER to enter the Stand-by mode.

Select a mode to be adjusted, using the channel down key. Example: VCO.

ADJUSTMENT PATTERN OPTION RESET

<---selected (violet)

VCO

AGC XX VCO XX GC XXX

SBT XX BC XX SCT XX VA XX SCR XX VS XX STT XXX HS XX GG XXX SS XX BG XXX SVC : MUTE

AGC XX RC XXX VCO XX SBT XX BC XX SCT XX VA XX SCR XX VS XX STT XXX HS XX GG XXX SS XX BG XXX SVC : MUTE

RC XXX

GC XXX

AGC XX XXX VCO XX SBT SCT SCR STT GG BG

XX XX XX VA XX XX VS XX XXX HS XX XXX SS XX XXX

ADJUSTMENT PATTERN OPTION RESET

RC GC BC

SVC : MUTE

XXX

3-1-3 Adjustment in Option Mode

This adjustment is necessary whenever the EEPROM is replaced. Input data (as marked on the back cabinet).

Select “SET OPTION” by pressing the Channel key twice.

Press the Volume +, - keys to enter the set Option mode.

Press MENU to go back to the factory mode.

Select RESET with channel key.

Press volume + key.

Alignment and Adjustments

3-2 Samsung Electronics

▼

3-1-4 Service Mode Adjustments

1. The Pattern Adjustment is done only in the factory. Do not attempt to readjust it.

2. Refer to 3-2 for other adjustments.

3. Set OPTION data.

3-1-5 Service Mode Adjustment Ratings

Note : The initial MICOM data values take effect when IC902 is replaced.

ADJUSTMENT PATTERN OPTION RESET

BYTE 0 : 0 0 BYTE 1 : 0 4

ADJUSTMENT PATTERN OPTION RESET

Item Function

1 AGC RF AGC Adjustment 0~63 50 2 VCO PIF VCO Adjustment 0~127 63 3 SCT SUB-CONTRAST Adjustment 0~63 48 4 SCR SUB-COLOR Adjustment 0~27 13 5 STT SUB-TINT Adjustment 0~27 7 6 RC RED-CUT OFF Adjustment 0~255 0 7 GC GREEN-CUT OFF Adjustment 0~255 0 8 BC BLUE-CUT OFF Adjustment 0~255 0

Range

Initalized

MICOM Data

ADJUSTMENT PATTERN OPTION RESET

POWER

OFF

9 SVC Input a Horiz line pattern 10 GG GREEN-GAIN Adjustment 0~255 127 11 BG BLUE-GAIN Adjustment 0~255 127 12 SBT SUB-BRIGHTNESS Adjustment 0~63 31 13 VA VERTICAL SIZE Adjustment 0~63 39 14 VS VERTICAL CENTER Adjustment 0 0 15 HS HORIZONTAL Phase Adjustment 0~31 15 16 SS SUB-SHARPNESS Adjustment 0~31 4

Alignment and Adjustments

Samsung Electronics 3-3

3-2 Alignment and Adjustment

3-2-1 General Alignment Instructions

1. Usually, a color TV needs only slight touch-up adjustment upon installation. Check the basic characteristics such as picture height, focus and a horizontal and vertical sync.

2. Observe the picture and check for good back and white details. There should be no objectionable color shading: If color shading is present, demagnetize the receiver. If color shading persists, perform purity and convergence adjustments described below.

3. To protect against shock hazard, use an isolation transformer.

3-2-2 Power Supply Check

Check the following: A: Power plug is connected; “Stand-by” mode B: Power On when “Power ON” button is pressed C: Power On by FBT Each supply is marked on

its lead-in wire. ( )

3-2-3 Focus Adjustment

Adjust the focus control on the FBT for well defined scanning lines.

3-2-4 Fail Safe Circuit Check (FS) (OPTION)

1. The failsafe check must be the final step in servicing.

2. Turn the power switch ON and adjust customer controls for normal operation.

3. Temporarily short pin X to pin R on the main board (RX06, RX04) with a jumper wire. Raster will disappear.

4. The TV must remain in this state even after removing the jumper wire. This shows that the failsafe circuit is working properly.

5. To recover picture and sound, temporarily turn off the TV and allow the failsafe circuit more than 30 seconds to reset. Then switch power ON to produce normal picture and sound.

3-2-5 IC902 Replacement

1. When IC902 is replaced, all values are reset to “Initialized MICOM Data” and readjustment is necessary.

2. Press the POWER button 10 seconds after plug-in.

3. To enter the Service Mode, refer to Fig. 3-1 (Service Mode Adjustment).

3-2-6 PIF VCO Adjustment

1. Use a Pattern Generator or an off-air signal.

2. Open pin 11 of Micom (IC901) or one side of lead pin for R237.

3. Adjust VCO in the service mode to set IC101 Pin 44 (AFT) to 2.5V ± 0.4V.

4. Connect the opened site.

3-2-7 RF-AGC Adjustment

1. Input a PHILLIPS pattern.

2. Set the input signal to 60 dB.

3. Enter into the AGC in the service mode.

4. Adjust AGC until color bar noise disappears.

Alignment and Adjustments

3-4 Samsung Electronics

3-2-8 Sub-Contrast Adjustment

1. Input a gray scale pattern. Use a pattern generator (PM5518).

2. Short D208 to switch off the ABL feed-back.

3. Check CN201 R-OUT with an oscilloscope.

4. Set RC, BC, GC data to 0 in the Service Mode.

5. Adjust SCT to 2.40 ± 0.1Vp-p

6. Remove the short across D208 and restore ABL.

3-2-9 Sub-Tint Adjustment

1. Input a rainbow pattern.

2. Check CN201 B-OUT with an oscilloscope.

3. Adjust STT in the service mode until the 6th peak is the highest and the 5th and 7th peaks have equal heights.

3-2-10 Sub-Color Adjustment

1. Do sub-color adjustment after the SubContrast and Sub-Tint adjustments.

2. D208 should still be shorted. The ABL should still be switched OFF.

3. Input a color bar pattern. Use a pattern generator (PM5518).

4. Check CN201 R-OUT (use an oscilloscope).

5. Ensure that the RC, GC and BC data are 0. BG are 140 and GG should be 90.

6. Adjust SCR to 2.4 ± 0.1Vp-p (black and red levels).

7. Remove the short across D208 and restore ABL.

2.5V 0.1Vpp

2.4V 0.1Vpp

Alignment and Adjustments

Samsung Electronics 3-5

3-2-11 White Balance Adjustment

3-2-11 (A) LOW-LIGHT ADJUSTMENTS

1. Input either a lion head or “pure white” color pattern.

2. Operate the receiver for 30 minutes.

3. Check the data in the service mode: RC, GC, BC are 0 and SB is 16; Steps BG are 90 and GG are 140.

4. Enter the horizontal line mode by pressing the MUTE key.

5. Adjust the screen VR on the FBT until a dim colored line (red,green or blue) appears on the screen.

6. After pressing the MUTE key, go to RC,BC or GC with channel , keys. After putting a dim colored line (red, green or blue) in the horizontal line with MUTE key, adjust color with volume , keys.

7. Exit the horizontal line via the MUTE key.

3-2-11 (B) HIGH-LIGHT ADJUSTMENTS

1. Input a high-light pattern

2. Adjust GG,BG in the Service Mode.

3. Recheck in low light.

3-2-12 Sub-Brightness Adjustment

1. Input a Toshiba pattern.

2. Warm up the receiver for 10 minutes.

3. Enter the Service Mode and set SB to the point where the 5th point is brighter in the gray scale.

3-2-13 Vertical Size Adjustment

1. Input a lion head pattern.

2. After the vertical center adjustment, enter into the service mode.

3. Adjust VA so that the each top and bottom of the screen is 4.0. If the top and bottom values are different, adjust VA so that the sum of the two values is 8.0.

3-2-14 Horizontal Size Adjustment

1. Receive a lion head pattern.

2. Enter into the service mode.

3. Adjust HS to symmetrized right and left.

3-2-15 When CRT Is Replaced

Do the following adjustments after the basic purity and convergence adjustments.

1. White Balance

2. Sub-brightness

3. Vertical Size

4. Horizontal Size

5. Fail safe (should be the final step).

4 3

2 1

▼

3-6 Samsung Electronics

BYTE:0

D7 D6

NAME

WIDE

AFT

AUTO

POWER ON

AUTO

SOUND MUTE

TV/Video

AUTO

POWER OFF

CATV

FUNCTION

Not Used

Analog (Tuner Input)

Not Used

Sound Mute

(during no signal)

TV/Video

Not Used

AIR/STD/HRC/IRC

Used

Digital (1 Chip Input)

Used

No Sound Mute

(during no signal)

Video Only

Power Off

(after 15 minute)

during no signal

AIR/STD/HRC/AFN

REMARK

1 for army

NT Only

3-3 Option Byte Table

Note: The option bytes are adjusted in the Service mode.

BYTE:1

D7 D6

D5 D4

D3 D2

D1 D0

NAME

TURBO

MTS

V-CHIP

FUNCTION

No Turbo function

No MTS function

No V-CHIP function

Turbo function exists

MTS function exists

V-CHIP function exists

Micom : SZM370TH

REMARK

+ 18 hidden pages