Sanyo CE28B5-C Schematic

Colour Television	CE28B5-C
Service Manual

Model CE28B5-C

Service Ref. No. CE28B5-C-00

PRODUCT CODE: 111354504

ORIGINAL VERSION: Chassis No. EB6-B

Give complete "SERVICE REF. NO." for parts
order or servicing, it is shown on the rating sheet
on the cabinet back of the TV set.
Note
This TV receiver will not work properly in foreign
countries where the television transmission
system and power source differ from the design
specifications. Refer to the specifications for the
design specifications
Contents
Safety precautions/Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . 2
Block diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 3~5
Cabinet Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 6
Adjustment and Repair Procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 7~11
CPU Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 12~13
Component Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 14~15
IC Block Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 16~20
Pin description of semiconductors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 21
Part Description and reading of schematic diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 22
Cabinet Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 23
Electric Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 24~31

Part No. SKSM0484

C3SEV

JULY 2001

SAFETY PRECAUTION

1:An isolation transformer should be connected in the power line between the receiver and the AC line when a service is performed on the primary of the converter transformer of the set.

2:Comply with all caution and safety-related notes provided on the cabinet back, inside the cabinet, on the chassis or the picture tube.

3:When replacing a chassis in the cabinet, always be certain that all the protective devices are installed properly, such as, control knobs, adjustment covers or shields, barriers, isolation resistor-capacitor networks etc. Before returning any television to the customer, the service technician must be sure that it is completely safe to operate without danger of electrical shock.

X-RADIATION PRECAUTION

The primary source of X-RADIATION in the television receiver is the picture tube. The picture tube is specially constructed to limit X-RADIATION emissions. For continued X-RADIATION protection, the replacement tube must be the same type as the original including suffix letter. Excessive high voltage may produce potentially hazardous X-RADIATION. To avoid such hazards, the high voltage must be maintained within specified limit. Refer to this service manual, high voltage adjustment for specific high voltage limit. If high voltage exceeds specified limits, take necessary corrective action. Carefully follow the instructions for +B1 volt power supply adjustment, and high voltage adjustment to maintain the high voltage within the specified limits.

PRODUCT SAFETY NOTICE

Product safety should be considered when a component replacement is made in any area of a receiver. Components indicated by mark ! in the parts list and the schematic diagram designate components in which safety can be of special significance. It is particularly recommended that only parts designated on the parts list in this manual be used for component replacement designated by mark ! . No deviations from resistance wattage or voltage ratings may be made for replacement items designated by mark ! .

	SPECIFICATIONS
Power source	AC 220~240V, 50Hz
Television system	System B/G
Colour system	PAL/NTSC4.43 (PAL/NTSC4.43/MTSC3.58 IN AV MODE)
Receiving channel	UHF: #21~69
	VHF: E2-E12
Aerial input impedance	75ohm
AV terminal
21 Pin SCART Terminal	AV1:CENELEC standard with RGB
	AV2:CENELEC standard with S-inputs
Front AV	AV3:RCA Terminal, Video and Audio (L/R)
Sound output(Music)	12W x 2
Dimensions (WxHxD)	736 x 597 x 494mm
Weight	32 Kg

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C3SEV

Q701

Outline

all fordiagramThisisa

DIAGRAMBLOCK

Aerial

Q711

Q721

A101

VIDEO-OUT

TUNER

20

Q242

R

R

X132

G

Q141

21

Q243

G

CRT

VIF

6

Q244

B

B

7

22

models

IC201

X131

PC-IN

POWER

SIF

9

TV-OUT

and

54

AV1

IF/VIDEO/

Q121~Q133

CHROMA/

TV-IN

25

26

13

SC-1

therefore

DEF

34

SIF-IN

2

8

I C BUS

35

3

44

BLK

BLK

15

43

C

C-OUT

15

SC-2

R

Y-OUT

AV2

45

B

16

39

Y

18

-3-

IC801

46

G

G

17

40

MONTO

differs

R

B

SYNC-IN

SCL

47

18

41

-OUT

EW-OUT

Refer also

IC803

24

CPU

32

26

to FIG.-2.

SDA

MEMORY

23

AV SELECTOR

H-OUT

T451

slightly

NICAM DECODER

60

CVBS-IN

FBT

61

T431

Q432

FOCUS

PROTECT-IN

19

1 - 15

the from

SCREEN

80 - 63

Q431

IC802

actual

ROM

PCC

CONTROL

D.Y

V-OUT IC501

CS

V

block

CONTROL

3

6

H

.diagram

C3SEV

AV Selector			IC1201
NICAM DECODER
			AV-SELECTOR
			<MM1313>
	K12H					Q1203
FRONT-AV	FRONT AV3		1(V)	(V)34	MONITOR-OUT
	MONITOR-OUT		2(L)			Q1202
			4(R)
SC-1	SC-1		13(V)	31		Y-IN
	(VIDEO/AUDIO-L/R)
			14(L)
SC-2	SC-2		16(R)					IC3451
			7(V)			C-IN
	(VIDEO/Y/C/AUDIO-L/R)			29
			8(L)					NICAM
			9(Y)			L-OUT
			10(R)	33			37	&
	K12J		11(C)	32	R-OUT		36 STEREO
					Y-OUT	Q1204/1207	<TDA9875>
			41(V)	37
	(VIDEO)						12
					C-OUT
				38		Q1205
IC201
IF/VIDEO/
CHROMA	C-OUT
	Y-OUT
	SIF-IN
IC001	AUDIO L/R-OUT					AUDIO-OUT	60
							61
AUDIO-OUT
I2C BUS		SDA/SCL					4
							5

Fig.-2

System Control

RC-IN

I2C BUS

25

CONTROL

SCL

IC803

24

MEMORY

SDA

23

19

POWER-FAIL

DETECT

POWER		KEY-IN		MUTE
26		28		40

44 BLK-OUT

45 B-OUT

46 G-OUT

IC801 47 R-OUT CPU

		60		CVBS
	1 - 7, 63 - 80		Q806
		61

IC802

ROM

Fig.-3

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C3SEV

Deflection Control

			IC501
		V-Output<LA7846>
		6	3
IC201	26	V-Drive
IF/VIDEO/			Q431
DEFLECTION			H-Output
<TB1251>		Q431	T431
			Drive Trans

32 H-Drive

D441

CS SW

41

Screen Width Control

EW-Out

Q461 Pcc Control

Q462

Deflection

Yoke

		Vert.
		Coil
		Horiz.
		Coil
	L461/L462	T451
		FlyBack Trans

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C3SEV

CABINET DISASSEMBLY

CABINET BACK DISASSEMBLY

			(A)
(A)		(A)

1. Remove 10 screws(A).

2. Pull out the cabinet back.

(A)

(A)

(A)

(A)

(A)

(A)

(A)

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C3VES

OPTION SETTING

[After replacing the Memory IC (IC803)]

The memory IC, IC803, stores the option data of TV set and service adjustments data for each circuit, therefore, when the memory IC is replaced, it should be performed following setting and “SERVICE ADJUSTMENT” on next page.

To enter to the Option Mode

+Press and hold the F/OK button on the remote control and P▼ button on the front panel of the TV. The option window will appear on the screen. Set the options as shown below.

OPTION

	ON-TIMER	ON
	SORT MODE	AUTO TUNE/SORT
	PLUG & PLAY	ON
	WELCOME TEXT	ON
	CODE TEST	OFF
	WSS	ON
	WIDE	OFF
	OPTION	UK
	312/313 Mode	OFF
	AV3 OPTION	ON
	3D SURROUND	ON
	ADJUST :	EXIT : RECALL

To set the option mode

+Highlight the desired option item by using the P▲ or P▼ button .

+To switch the option mode, use the Volume - (LEFT) or Volume + (RIGHT) button.

+The data which is set in the option mode is stored into the memory IC automatically.

Following table shows the available option items and default setting mode.

Option Mode	Mode	Description & Note
ON-TIMER	ON or OFF	On-timer available, default “ON”
SORT MODE	AUTO TUNE/SORT	Tuning mode, default “AUTO TUNE/SORT”
	or AUTO TUNE
	or ATS EURO PLUS
PLUG & PLAY	ON or OFF	Plug & Play mode, default “ON”
WELCOME TEXT	ON or OFF	Display message when first set up, default “ON”
CODE TEST	OFF or ON	For factory use, default “OFF”
WSS	ON or OFF	Wide Screen Signaling available, default “ON”
WIDE	ON or OFF	Wide mode, default “ON”
OPTION	UK or IRELAND	Destination option , default “UK”
312/313 Mode	ON or OFF	Teletext mode, default OFF
AV3 OPTION	ON or OFF	Front AV disable, default ON
3D SURROUND	ON or OFF	3D Surround available, default ON

Exit from the Service Mode

+ Press the RECALL button.

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C3SEV

SERVICE ADJUSTMENTS

Note: Some items of the service adjustments for this chassis are controlled by the CPU, IC801, and the adjustments are carried out by using the RC handset.

[After replacing the Memory IC (IC803)]

The memory IC, IC803, stores the service adjustments data for each circuit, therefore, when the memory IC is replaced, it should be performed “OPTION SETTING” on previous page and the following adjustments, refer to further adjustment on page 14.

ADJUSTABLE SERVICE ADJUSTMENT

REGULAR

	Item No.	OSD	Description
	1	AGC	AGC Adjustment
	2	CUT	Cut-Off Drive Adjustment
	3	GRY	G-Drive Adjustment
	4	GRY	B-Drive Adjustment
	7	HBP	H-Blanking Phase Adjustment
	8	OSD	OSD Positioning Adjustment
WIDE
	Item No.	OSD	Description
	1	P V-P	Vertical Centre Adjustment
	2	P H-P	Horizontal Centre Adjustment
	5	P V-S	Vertical Size Adjustment
	6	P H-S	Horizontal Size Adjustment
	7	P PCC	Pcc Adjustment
	8	P TRP	Trapezoid Distortion Adjustment
	10	P CNR	Corner Adjustment

IMPORTANT NOTICE

Do not attempt to adjust service adjustments not listed on the above otherwise it may cause loss of performance and product safety.

To enter to the Service Mode

+Press and hold the GREEN button on the remote control and then press the P▼ button inside of the door. The adjustment window will appear on the screen.

ADJUST
REGULAR
WIDE
OTHERS
TB1251
SELECT:	OK
EXIT : RECALL

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C3SEV

To select the mode and service item and change data value

+Highlight the desired adjustment mode by using the P▲ or P▼ button and then press the F/OK button.

+To select the adjustment item, use the P▲ or P▼ button.

+To change the service data, use the Volume -(LEFT) or Volume + (RIGHT) button.

+The data which is set in the service mode is stored into the memory IC automatically.

REGULAR mode

WIDE mode

REGULAR
1, AGC	38

WIDE
1. P V-P	1F

Adjustment No.	Adjustment Data	Adjustment No.	Adjustment Data
and Item name		and Item name

Exit from the Service Mode

+ Press the RECALL button or turn off the TV set by using the Mains switch.

INITIALISATION OF MEMORY IC

To initialise the memory IC (IC803), press and hold the NORMAL button on te remote control and then press the P▲ button on the front panel of the TV set, and then turn the Mains switch Off and On. Now the initialisation is completed.

When initialised the memory IC, all of the setting data (option data and service adjustment data) stored in the IC are reset to the default value. So it is necessary to set the option settings and readjust the service adjustments listed on left page.

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C3SEV

ADJUSTMENTS

IMPORTANT NOTICE

Do not attempt to adjust the following service adjustments except when adjustments are required in servicing otherwise it may cause loss of performance and product safety.

+B VOLTAGE ADJUSTMENT

1.Receive white raster pattern.

2.Set controls to normal.

3.Connect digital voltmetre to test point TP-B and GND.

4.Adjust voltage to 150 ±0.5V by using VR641.

AGC ADJUSTMENT

1.Input and tune an RF signal which is UHF to the clearest station.

2.Connect digital voltmetre to test point TP-A and GND.

4.Enter to the service mode and select mode “REGULAR”, and select item no.1 “REGULAR 1, AGC”.

5.Press the LEVEL+ or LEVEL - button to adjust voltage to be 3.2Vdc.

FOCUS ADJUSTMENT

By using FOCUS VR, adjust focus control for well defined scanning lines.

GREY SCALE ADJUSTMENT

SCREEN ADJUSTMENT

1.Receive black & white pattern.

2.Enter to the service mode and select mode “REGULAR”, and select item no. 2 “REGULAR 2, CUT”. The horizontal line will appear on the screen.

3.Set the SCREEN VR for one colour to be just visible.

4.Using the numeric buttons shown set each colour to minimum by decreasing to the point where any further

decrease resets the adjustment to maximum value.

BIAS ADJUSTMENT

5.By using the buttons 1, 2, 4, 5, 7, 8 on the remote control, adjust the line to be white.

The key allocation is as follows;

Button No. Operation

1Increase Red

2Decrease Red

4Increase Green

5Decrease Green

7Increase Blue

8Decrease Blue

DRIVE ADJUSTMENT

6.Select item no.3 “REGULAR 3, GRY” (G-Drive) or 4 “REGULAR 4, GRY” (B-Drive) and adjust both initially to 3F.

7.Change data value of each item by using LEVEL + or LEVEL - button to obtain the proper white balance.

PCC ADJUSTMENT

PCC ADJUSTMENT

1.Receive cross hatch pattern and set screen mode to “FULL”.

2.Enter to the service mode and select mode “WIDE”, and select item no. 7 “WIDE 7.P PCC”.

3.Press the LEVEL+ or LEVEL - button to adjust the vertical line to be straight.

TRAPEZOID ADJUSTMENT

1.Receive cross hatch pattern and set screen mode to “FULL”.

2.Enter to the service mode and select mode “WIDE”, and select item no. 8 “WIDE 8.P TRP”.

3.Press the LEVEL+ or LEVEL - button to correct the trapezum distortion of the vertical line.

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C3SEV