HITACHI 50V720, 50VF820, 55VF820, 60VF820, 50VG825 Service Manual

January 2006 (ver a)

HITACHI

PROJECTION TELEVISION

2006 MODEL RELEASE DIGITAL HD READY LCD

Model	Chassis	Remote	P/N
50V720	LC-57	CLU-4352UG2	HL02073
50VF820	LC-58	CLU-3842WL	HL02062
55VF820	LC-58	CLU-3842WL	HL02062
60VF820	LC-58	CLU-3842WL	HL02062
50VG825	LC-58E	CLU-3851WL	HL02065
55VG825	LC-58E	CLU-3851WL	HL02065
60VG825	LC-58E	CLU-3851WL	HL02065

Service Web Site

http://www.hitachiserviceusa.com

CONTENTS... 2006 LC-5X Chassis Projection Television Information

Materials Prepared by… Alvie Rodgers C.E.T. (Chamblee, GA.)

LC-5X BLANK PAGE “USE FOR NOTES”

INTENTIONALLY LEFT BLANK

Materials prepared by

January 2006 (ver a)

LC-5X TABLE OF CONTENTS

Alvie Rodgers C.E.T.

TOPICS

PAGE

SECTION (1) POWER SUPPLY DIAGRAMS:

• Generic Power Supply Circuits Explained ------------------------------------

01-01

• A Out Shutdown Diagram ---------------------------------------------------------

01-03

• B~E Out Shutdown Diagram -----------------------------------------------------

01-04

• F Out Shutdown Diagram ---------------------------------------------------------

01-05

• F In Shutdown Diagram -----------------------------------------------------------

01-06

• 5V Standby Regulation Circuit Diagram -------------------------------------

01-07

• 5.6V Regulation Circuit Diagram -----------------------------------------------

01-08

• Power On Circuit Diagram -------------------------------------------------------

01-09

SECTION (2) VIDEO CIRCUIT INFORMATION:

• Video Signal Selection Circuit Diagram -------------------------------------

02-01

SECTION (3) AUDIO CIRCUIT INFORMATION:

• Audio Signal Selection Circuit Diagram -------------------------------------

03-01

• Audio Woofer Circuit Diagram --------------------------------------------------

03-02

SECTION (4) PWB PART NUMBERS AND REAR INPUTS:

• LC-58 PWB Part Numbers -------------------------------------------------------

04-01

• LC-58E PWB Part Numbers -----------------------------------------------------

04-02

• LC-57 PWB Part Numbers -------------------------------------------------------

04-03

• LC-57 and LC58 Rear Inputs ---------------------------------------------------

04-02

SECTION (5) THINGS YOU SHOULD KNOW:

• See the index for this section after the Section 5 Divider.

---------------- 05-00

Table of Contents Page 1

LC-5X BLANK PAGE “USE FOR NOTES”

INTENTIONALLY LEFT BLANK

POWER SUPPLY INFORMATION

LC-5X

CHASSIS INFORMATION

SECTION 01

LC-5X BLANK PAGE “USE FOR NOTES”

INTENTIONALLY LEFT BLANK

LC-5X GENERIC POWER SUPPLY SHUTDOWN EXPLANATION

GENERIC POWER SUPPLY SHUTDOWN INFORMATION:

The Protect Circuit has been broken down into 4 distinct Sections. The input/outputs are identified by letters in circles (A) ~ (F). These Circuits are involved in the Shutdown inputs which shuts off the Power Supply in the LC-5X Chassis.

UNDERSTANDING SYMBOLS ON THE DIAGRAMS:

(Sheet 13)

In the case of the LC-58 Chassis, the Schematics are shown between pages 129 ~ 151. This represents 23 individual pages within the Service Manual PA-0210. To help identify the location of particular drawings, you will notice comments like “Sheet 13”. In this case, the diagram is taken from the 13th page of the Schematics shown in the Service Manual .

(17)

On the Power Supply Shutdown circuit diagrams you will notice small number at different locations along the shutdown path. The small numbers represent the number of shutdown “events” that are possible at this point in the circuit. As the lines continue, the numbers will grow and they are cumulative.

To help with Inputs and Outputs from the distinct Sections of the drawings, Symbols as shown on the left are used. This will help the Technician navigate between drawings more easily.

GENERIC SHUTDOWN CIRCUITS EXPLAINED:

The following circuits are commonly used in Hitachi LCD product and relate to the drawings used for Shutdown:

VOLTAGE TOO HIGH DETECTION

(See Figure 1)

This circuit is the Voltage Too High Detection circuit. In the example shown in Figure 1, the zener diode Z01 is connected to a voltage divider R01 and R02. If the voltage source rises too high, the voltage at the divider center point will rise as well and trigger or fire the zener diode which produces a Shutdown signal through D02 and on to the appropriate circuit.

VOLTAGE LOSS or SHORT DETECTION

(See Figure 2)

One circuit used is the Voltage Loss or Short Detection circuit. This is a very simple circuit that detects a loss of a particular power supply and supplies a Pull-Down path for the base of a PNP transistor Q1. This circuit consist of a diode connected by its cathode to a positive B+ power supply. Under normal conditions, the diode is reversed biases, which keeps the base of Q1 pulled up, forcing it OFF. However, if there is a short or excessive load on the B+ line that’s being monitored, the diode in effect will have a LOW on its cathode, turning it ON. This will allow a current path for the base bias of Q1, which will turn it ON and generates a Shutdown Signal.

		Any Power Supply
Z01	R01	Voltage Too
	R02	High Detector
D02
		Shutdown
		Signal
	Figure 1

		Any Positive
	Voltage	B+ Supply
		B+
	Loss
	Detector	Q1
	Figure 2	Shutdown Signal

(Continued on next page)

PAGE 01-01

LC-5X GENERIC POWER SUPPLY SHUTDOWN EXPLANATION

GENERAL INFORMATION:

This explains the Overall Power Supply Shutdown Circuits: Which turns off the Relay Drivers Q942, Q943 and Q944.

There are Four Relays which are activated when Power 1 and Power 3 go high. These Relays are all protected (turned off) by the 17 possible shutdown inputs.

•RELAY S901 Controlled by Power 3 to Transistor Q942:

This relay supplies AC to Relay S902 and S903 explained below.

•RELAY S902 Controlled by Power 1 to Transistor Q943:

This relay supplies AC to the Signal Power supply Bridge Rectifier D902.

•RELAY S903 Controlled by Power 3 to Transistor Q944:

This relay supplies AC to the Lamp Power PWB.

•RELAY S904 Controlled by Power 3 to Transistor Q944:

This relay supplies B+ to the Audio Circuit.

Q980 and Q981 Relay Inhibit Activation. (SHUTDOWN) called COMMON ACTION CIRCUIT.

All 17 Shutdown events will cause the above mentioned relays to turn off. This action will stop all secondary power supplies.

See the LC-5X Protect (F In) Shutdown Circuit for details.

If any of the shutdown circuits activate, the base of Q980 will go High. This turns on Q980 and removes the Power On Highs from PPT3 connector pins 6 and 2 called Power_1 and Power_3. With this, the main power supplies will STOP. Q981 operates as a “latch”. This prevents Q980 from turning off if the shutdown signal disappears after shutdown.

SOME SHUTDOWN CIRCUITS ARE DEFEATED IN STANDBY MODE. (Set Off).

When the set is turned off (called Stand By), some of the shutdown inputs are not active because the voltages being monitored are not on.

SHUTDOWN INPUTS EXPLAINED:

GENERAL INFORMATION CONTINUED: (See previous page for generic shutdown circuit details):

All of the Power Supply Shutdown circuitry can be broken down into the following categories;

•Voltage Missing Detection or Short Detection

•Voltage Too High Detection

Note: The Fan failure or “Stopped” alarms work the same as voltage too high detection. Normally when a fan is running, the pull-up resistor attached to the Fans B+ will not be allowed to pull up high due to the Fans internal Hall element’s action when the Fan is rotating. If the fan stops, the Pull-Up resistor will pull the shutdown signal “Alarm” up high. (See (B~E Out) Protect shutdown diagram).

The Door open signal works the same. A mechanical switch is located in such a fashion that when the door is closed, the switch is activated. This in turn pulls the door alarm voltage low and will not allow an “Alarm” to be generated as long as the door is closed. (See (B~E Out) Protect shutdown diagram).

Lamp Alarm. A mechanical switch is located in such a fashion that when the Lamp is installed, the switch is activated. This in turn pulls the door alarm voltage low and will not allow an “Alarm” to be generated as long as the Lamp is installed and the Lamp door is closed. (See (B~E Out) Protect shutdown diagram).

Temp Sensor. The Temperature sensor is normally in a state of Low Ohms. This prevents the Pull Up resistor from generating a Temperature Alarm. If the Fan Duct gets too hot, the Temperature Sensor resistance goes up and the Temperature alarm is generated. (See (A Out) Protect shutdown diagram).

PAGE 01-02

LC-5X (A Out) PROTECT SHUTDOWN DIAGRAM

Drive Sheet 15

The Protect Circuit has been broken down into 4 distinct Diagrams. The input/outputs are identified letters in circles (A) ~

(F). This Circuit begins the Shutdown input which shut off the Power Supply in the LC-58 Chassis. The Schematic are shown on 23 pages within the Service Manual PA-0210. This section is taken from the Drive Circuit on the 15th page of the Schematics shown in the Service Manual .

+5.6V

2

I801

4

3.8V

D801

1	I804	8	+3.3VM
3		7

D806

2

I808

4

+3.3V

				D805
From D801 Anode Monitors +3.8V from I801 Pin 4
From D805 Anode Monitors +3.3V from I808 Pin 4
From D806 Anode Monitors +3.3VM from I804 Pin 7 and 8
				See (B~E out) Protect
		Drive Sheet 19		Shutdown Diagram
				PDT
	Temp Sensor normally Low Ohms (Closed).
	High Temp High Ohms (Open).			10	PROT DRV
				PROT SW	Normal
	SBY +5V
					A
	PDE		R6M7		Active
	R6D1	R6M1	0 Ohm	R688
					TEMP_ALARM
	2	Q604		9
	R602
Temp	3
Sensor
On Lamp	R6M0	R6M6
Housing
		0 Ohm
					PAGE 01-03

	LC-5X (B~E Out) PROTECT SHUTDOWN DIAGRAM
			Fan Sheet 13			RF28
					Sby +5v		PTW1
		1
E	DooR							1	To Door Sw PWB
									on Control
	Alarm
				DF08		RF29			Sheet 22
		QF01
	Fan
					CF15	DF07
	Prot							PFA1
					DF05				For Optical Engine
D	Fan	4						1	Fan Alarm
	Alarm					RF39
					Fan 12V			2	Fan +10V
	SW +16.5V	5	IF02	3				3	Fan Gnd
					DF03			PFA3	For Lamp
To DM/Power I/F			2
	Sheet 11							1	Fan Alarm
						RF41
See (F Out)								2	Fan +10V
	Protect
Shutdown								3	Fan Gnd
	Diagram
					DF01			PFA4	For Chassis
	Power							1	Fan Alarm
	3					RF42
								2	Fan +10V
								3	Fan Gnd
					DF04			PFA6	For Digital Module
								1	Fan Alarm
			2			RF38
		5	IF03	3	Fan 10V			2	Fan +10V
						RF34
								3	Fan Gnd
						0 Ohm
			RF26					PDT
C	Temp	1					1	9	TEMP ALARM
	Alarm
									To Drive Sheet 15
	Prot		RF27
B							3	10	PROT SW
	DRV	3
									A
						See (A) Protect
						Shutdown Diagram

PAGE 01-04

	LC-5X (F Out) PROTECT SHUTDOWN DIAGRAM
Fan +10V	Fan +12V					See (B~E) Fan Protect
		B	PRoT
				To Fan Drive			Circuit Diagram
			DRV	Sheet 13		To Fan Drive Sheet 13
						DooR	Temp	Fan
RJ32	RJ34					Alarm	Alarm	Alarm
			4			1	1	4
			DJ04	DJ23	DJ25	E	C	D
DJ16
	DJ22
DJ15			RJ31			RJ05	RJ06	RJ07
		DJ21
			DJ17	DJ18		DJ00		DJ01
	RJ3O	CJ08					1	5
QJ06
				5
	DJ15						6

5

11

See (F In) Protect
Shutdown Circuit Diagram	To Power
for Continuation.	Sheet 20

PPT3

Active

Normal

7	F	15
		< Protect >

Sig + 5.6V

Sig + 10.5V

Sig + 16.5V

4

	DJ08	RJ08	RJ10	DJ11
		CJ04
QJ02	RJ17
				1
			DJ07	DJ10
RJ18	Sig +10.5 & 16.5 V			16.5 V Too High
	Loss Detection			Detection
RJ19		CJ03
DJ09
				3
			DM/POWER/I/F Sheet 11

PAGE 01-05

LC-5X PROTECT (F In) SHUTDOWN CIRCUIT

06-01 PAGE

From Sub	From Digital					See Protect (F Out)
Micro	Module
						Shutdown Circuit Diagram
Pin 20, Q021, Q025	Pin 81
		PPT3	Audio Vcc			for Inputs.	F
Power 1	Power 3
6	2		11	12	13		7	15
off on	off	on					<PROTECT> Active
		SBY +5V			Raw B+	F903		Normal
						4

SBY +5V

R946

R947

S901

AC

D902

R924

2.2 ohm

From S901

AC

D940

F904

For

S902

Q942

For

AC

AC

R925

D958

D944

Signal

D941

R944

S902

6

Power

Relay

S903

Supply

D946

R943

R940

T902

D902

Driver

Q943

D945

SBY +5V

Hot

D915

9V

(8.9V ~ 9.3V)

Relay

Ground

S903

From S901

Audio B+

R926

Driver

R941

AC

2.2 ohm

S904

R927

F904

Audio

PPT3

Vcc

C916

D942

3

D943

AC 175 On

Power		To Lamp Power				Q901		I905	SBY 5V
					Sig +10.5V
Sheet 20	R945			Q944
						2			4
				Relay
	D951 D947 D948		R942			I902
D950				Driver		Run B+ 19V
R980	C980	Q981			D988		1		3
Q980		R982			D990	R923	D959		1
					1
									15
		R981	17		Excessive Sig +10.5V		AC Voltage Too High
		C981			Voltage Detection			Detection

LC-5X (STB 5V) Stand By Power Supply

	D901		F902				T901	+7.5V
		+						D949
AC	-							1
			C908					C940
						5
			3		I901	7
						8
				1	4	2
						D906	R906
						C912
	R908	R908		R908
							I904	R957
							4
								1
		C911				D907		R958
						5.6V
							3	2
								D962
								6.8V
						Power
						Sheet 20

		PPT2
I942	3	17	SBY +5V
2	C957

PAGE 01-07

	LC-5X CHASSIS POWER SUPPLY SIGNAL 5.6V REGULATION
1 of 3
T902	7.5P/P						Power
9
							Sheet 20
											Sig +10.5V
	D913	C925
11			D914				Hot Ground from negative
							side of bridge rectifier D902			FB	R963
From LP06 pin 4				Run						I906
Supplied from Relay S903											8.6V
									3		1
C926		D910	19.3V		9				4.4V		R964
									4
					Vcc						2
						10			2.1V		7.6V
	D909				OCP/FB
								R921
1/2 AC		Start Up	5				R922		C930	Regulator
		C933			I902	17			Photocoupler
AC Supplied from							C929
			1	Driver/		18
Relay S902				Output IC
Raw B+ from D902		163.6V	20	D	S	11	R962	R961	C950
150V	2 of 3		21
	T902								3
	4				R916		Sig +5.6V			7.6V
F903									I941
					R917
					R918				1

	All 0.47		2.4V
		R966		2
6

3 of 3	10K	PPT2
T902
16	E942	4.59A
	Sig +5.6V	1
	1	2
15	D955
14	2	3
	C948
		4	Sig +5.6V
	3
		5
		6
		7
	Cold Ground from pin
	14, 17, 20 of T902

PAGE 01-08