Hitachi C21-TF641S, C21-TF641SN, C21-TF641ST, C21-TF641SNT, C21-TF651S Service Manual

HITACHII I HCPT T1-001

C21-TF641S/SN/ST/SNT

C21-TF651S/SN/ST/SNT

SERVICE MANUAL C21-TF751S/SN/ST/SNT C21-TF571S/SN/ST/SNT

T1 Chassis

CAUTION : Before servicing this chassis, it is important that the service techician reads the " Safety Precaution " and " Product Safety Notices " in this Service Manual.

CONTENTS
SAFETY PRECAUTIONS ...………………...…………….……………………………………………	2
PRODUCT SAFETY NOTICE …………...…………….………...……………...…………….………	2
REMOTE CONTROL UNIT ……………..………...…………….………………………………………	3
GENERAL OPERATIONS GUIDE .………………...…………….……………………………………	4
CIRCUIT DESCRIPTION …………...…………….……………………………………………………	5
ADJUSTMENT INSTRUCTIONS ……………………...…………….…………………………………	6
REPLACEMENT PARTS LIST …………………...…………….………………………………………	12

SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT.

COLOR TELEVISION

MARCH 2005	Hitachi Consumer Products ( THAILAND ) , Ltd.

SAFTY PRECAUTIONS

WARNING: The following precautions should be opserved.

1.Do not install , remove, or handle the picture tube in any manner unless shatter proof goggles are worn. People not so equipped should be kept away while picture tubes are handled. Keep picture tube away from the body while handing.

2.	When		service is required, an isolation					transformer
	should		be	inserted between			power	line and the
	receiver before				any	service	is performed on the
	chassis.
3.	When		replacing		the	chassis	in the cabinet,ensure
	all	the protective devices are put back in place,such
	as	barriers,		non - metallic knobs, adjustment or

compartment covers or shields, isolation resistors/ capacitors, etc.

4. When service is required, observe the original lead dressing. Extra precaution should be taken to

assure correct lead dressing in the high voltage circuitry area. Particularly note the R. G. B. lead dressing. Ensure they are dressed well away from the horizontal scan and F.B.T. circuitry.

5. Always use the manufacturer ' s replacement component. Always replace original spacers and maintain lead lengths. Especially critical components are indicated thus on the parts list and should not be replaced by other makes. Furthermore, where a short circuit has occurred, replace those components that indicate evidence of overheating.

6.Before returning a serviced receiver to the customer, the service technician must thoroughly test the unit to be certain that it is completely safe to operate without danger of electrical shock, and be sure that no protective device built into the instrucment by the manufacturer has became defective, or inadvertenly damaged during servicing. Therefore, the following checks are recommended for the continued protection of the customers and service techninians.

INSULATION

Insulation resistantce should not be less than 4.5 Mohm at 500 VDC between the mains poles and any accessible metal parts. Also, no flashover or breakdown should occur during the dielectric strength test, applying 3.2kV AC for two seconds between the main poles and accessible metal parts.

HIGH VOLTAGE

High voltage should always be kept at the rated value of the chassis and no higher. Operating at higher voltages may cause a failure of the picture tube or high voltage supply, and also, under certain circumstances could produce X-radiation moderately in excess of design levels. The high voltage must not, under any circumstances, exceed 32kV on the chassis.

X-RADIATION

TUBES : The primary source of X - radiation in this receiver is the picture tube. The tube utilized for the above mentioned function in this chassis is specially constructed to limit X - radiatuion.

For continued X-radiation protection, replace tube with the same type as the original, HITACHI approved type.

PRODUCT SAFETY NOTICE

Many electrical and mechanical parts in HITACHI television receiver have special safety related characteristics. These characteristics are often not evident from visual inspection, nor can be protection afforded by them necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified by marking with a on the schematics and replacement parts list in this Service Manual.The use of a substitute

replacement component which does not have the same safety characteristics as the HITACHI recommended replacement one, shown in the parts list in this Service Manual, may create electrical shock, fire, X - radiation,

or other hazards.

Product Safety is continuously under review and new instructions are issued from time to time. For the latest information,always consult the current HITACHI Service Manual. A subscription to ,or additional copies of HITACHI Service Manuals may be obtained at a nominal charge from your HITACHI sales offices.

TUBE DISCHARGE

The line output stage can develop voltages in excess of 25 kV; if the E.H.T cap is required to be removed, discharge the anode cap to chassis via a high value resistor, prior to its removal from the tube.

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REMOTE CONTROL UNIT

	2		2
	1	5	1	5
	19	17	19	17
	16	18	16	18
		14		14
		4		4
			20	9
		8		8
	10	9	10
	6	12	6	12
		3		3
	7		7
		15		15
	11	13	11	13

	Models without Teletext		Models with Teletext
1.	POWER ON/OFF SWITCH	11.	DEFAULT
2.	INPUT SELECTOR	12.	MUTE
3.	VOLUME UP/DOWN	13.	CHI/II (FOR NICAM/A2 MODELS)
4.	PROGRAMME UP/DOWN	14.	PROGRAMME SELECTOR (DIRECT KEY)
5.	RECALL	15.	CURSOR
6.	SURROUND SOUND	16.	RETURN
7.	MENU	17.	COLOR SYSTEM
8.	TIMER	18.	SOUND SYSTEM
9.	PICTURE	19.	EQUALIZER
10.	SOUND	20	T/TEXT FUNCTION KEY (T/TEXT MODELS ONLY)

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GENERAL OPERATIONS GUIDE

With this set, all adjustments/settings are performed by selecting from menu screens. of adjustments/settings are shown below. To access the menu screen, press the MENU

Different menu screens and details button, then select the item by

pressing the up/down cursor buttons

and adjust by the left/right cursor buttons

.

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BLOCK DIAGRAM

- 5 -

ADJUSTMENT INSTRUCTIONS

HOW TO GO TO SERVICE MODE

1.How to go to adjustment mode no 001 ~ 022 Procedure

(1)Turn TV off by power switch on the TV set.

(2)Press " FUNCTION " button on the TV set and kept depress the button.

(3)Turn TV on by power switch on the TV set.

2.How to go to adjustment mode no 101 ~ 328

Procedure
(1)	Set volume to be “0”.
(2)	Press	button on remote control to go to standby mode.
(3)	Press “TV/VIDEO” button on the TV set, and kept depress the button.
(4)	Press	button on remote control to go to operation mode.
(5)	TV will show service table,then please cancel to keep depress the "TV/VIDEO" button.

Note : 1. Press the UP/DOWN cursor buttons		to select adjustment mode no.
	2. Adjust data by the left/right cursor buttons	.
	3. Press "RECALL" buttons to restore the data.
+B ADJUSTMENT
	PREPARATION				PROCEDURES
1	AC input voltage 230 + 5V(50Hz)		1	Adjust R954 to obtain +B voltage as below
2	Turns on the set and set the brightness and contrast			+B voltage : TP902
	to Max.(Signal : Philips Pattern)			GND	: TP901
3	After 30 sec heat-run, check & adjust the +B voltage
FREE RUN FREQUENCY ADJUSTMENT
	PREPARATION				PROCEDURES
1	Receive a PAL-I monoscope signal on TV mode.		1	Select adjustment mode no. 1 and press "MENU" button
				one time.
VIF-VCO FREE RUN FREQUENCY ADJUSTMENT
	PREPARATION				PROCEDURES
1	Receive a PAL-I monoscope signal on TV mode.		1	Select adjustment mode no. 2 and press "MENU" button
				one time.

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SOUND TRAP FREQUENCY ADJUSTMENT

PREPARATION

PROCEDURES

1

Receive a PAL-I monoscope signal on TV mode.

1

Select adjustment mode no. 3 and press "MENU" button

one time.

SECAM R-Y OFFSET ADJUSTMENT

PREPARATION

PROCEDURES

1

Receive a secam color bar signal on Video 2.

1

Select adjustment mode no. 4.

2

Connect oscilloscope probe to pin 5 of E701.

2

Adjust output level at pin 5 of E701 as indicated below

using service mode no. 4.

0 + 0.1 V

SECAM B-Y OFFSET ADJUSTMENT

PREPARATION

PROCEDURES

1

Receive a secam color bar signal on Video 2.

1

Select adjustment mode no. 5.

2

Connect oscilloscope probe to pin 5 of E701.

2

Adjust output level at pin 5 of E701 as indicated below

using service mode no. 5.

0 + 0.1 V

WHITE PEAK LEVEL ADJUSTMENT

PREPARATION

PROCEDURES

1

Connect oscilloscope probe to pin 3 of E202 on CPT

1

Adjust output level at pin 3 of E202 as indicated below

P.W.B with respect to ground.

using service mode no. 15.

2

Input PAL cross hatch signal to Video 2 terminal.

Cross hatch signal input level : 1 Vpp + 10%(with load

A

75 ohm) or 2 Vpp + 10%(no load).

3

Set CONTRAST to MAX.

1H

4

Set data in adjustment mode no.15 to 90.

A = 2.8 + 0.1Vpp

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VERTICAL SHIFT ADJUSTMENT

	PREPARATION			PROCEDURES
1	Preheat more than 5 minutes of power supply.	1	Select the IIC control address No. 11.
2	Receive PAL Philips pattern signal.	2	Set the horizontal center line to vertical center maker
			of CRT by adjustment of IIC.

Vertical center marker of CRT

VERTICAL SIZE ADJUSTMENT

PREPARATION

PROCEDURES

1

Preheat more than 5 minutes of power supply.

1

Select the IIC control address No. 12.

2

Receive Philips pattern signal.

2

Adjust IIC data to obtain the following conditions.

PAL

3 Check vertical amplitude as below by NTSC circle pattern.

NTSC

4 If picture isn't center, go back to IIC control No. 11 and adjust IIC data to obtain the following conditions.

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HORIZONTAL CENTER ADJUSTMENT

	PREPARATION		PROCEDURES
1	Side pin adjustment should be already completed.	1	Adjust adjustment mode no. 13 so that the average
2	Receive circle pattern signal.		reading of R and L is 2.0 + 0.5 at circle pattern signal.

FOCUS ADJUSTMENT

PREPARATION

PROCEDURES

1

Receive Philips pattern signal.

1

Set picture to mode 1

2

Vertical amplitude adjustment should be already

2

Turn the focus VR gradually clockwise from the full

completed.

counterclockwise and adjust so that the halo of vertical

3

Adjust the cut-off after pre-adjust focus VR.

center line does not appear, and horizontal line is

4

Check the cut-off in case focus is re-adjusted

MIN. width.

HORIZONTAL

1 2 3 4 5 6 7

NO.5

HALO

ZOOM

VERTICAL

WHITE BALANCE ADJUSTMENT

PREPARATION

PROCEDURES

1

Adjust the W/B after the Power is turned ON for 20 minute

1

Turn the screen adjusting VR clockwise and set it to the

2

Purity adjustment should be completed.

position where the bright line starts appearing on CPT

3

Set the vertical incident illumination on the CPT surface

screen.

to 20 lux or less.

2

Take the first appeared color as the reference. Adjust the

4

Receive white raster signal.

other colors by remote until both appear to be the same

5

Set adjustment mode data as table on the next page

level as the reference. (A white horizontal line is seen at

to default.

the CPT center.)

Disp No

ITEM

Default

Low brightness adjustment data

016

R-CUTOFF

127

Red

………. ”1” key for up, “4” key for down.

017

G-CUTOFF

127

Green

………. ”2” key for up, “5” key for down.

018

B-CUTOFF

127

Blue

………. ”3” key for up, “6” key for down

019

R-DRIVE

63

Don’t change the data of the reference color

020

B-DRIVE

63

3

Exit the lateral line mode. (Press “MUTE” by remote).

021

SUB-BRIGHT

127

4

Set white balance meter at the center of the screen.

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WHITE BALANCE ADJUSTMENT(Continued)

PREPARATION

PROCEDURES

6

Turn the screen adjustment VR fully counterclockwise.

5

Adjust brightness control so that the indication of the

7

Set to lateral line mode by Press “MUTE” button on

brightness meter is a prescribed value of brightness

remote control .

adjustment. Adjust white balance with the white balance

control data (Red/Blue).

High brightness adjustment data

Red

………. ”7” key for up, “0” key for down.

Blue

………. ”8” key for up, “9” key for down.

SUB-BRIGHTNESS ADJUSTMENT

PREPARATION

PROCEDURES

1

Turn the TV set on and heat run for 20 minutes or more.

1

Press "PICTURE" key until go to picture mode 2.

2

Horizontal size adjustment and side pin adjustment

2

The sub-brightness should be adjusted (Adjustment

should be completed.

mode no. 21) using11 steps gray scale (A1-A1)

of color

3

Receive Philips pattern signal.

bar pattern

Set picture mode 2 as shown below.

3

Adjust until A10 is complete black and A9 is lightly black.

4

Go out from service mode.

CONTRAST

:

0

COLOR

:

0

BRIGHTNESS

:

50

A

A

A

A

A

A

A

A

A

A

A

11

10

9

8

7

6

5

4

3

2

1

5

Adjust

picture mode 2 as below.

CONTRAST

:

100

COLOR

:

60

BRIGHTNESS

:

50

6

Press "PICTURE" key until go to picture mode 1.

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