Hitachi KH-WS1-W Service Manual

No. 0096E

KHWS1W KHWS1WUN

CONTENTS

SPECIFICATIONS ..................................................................................................................................................... 2

SERVICE POINTS .....................................................................................................................................................3

ADJUSTMENTS ......................................................................................................................................................... 7

TROUBLESHOOTING ............................................................................................................................................... 10

BLOCK DIAGRAM OF ANTENNA AND TUNER UNIT............................................................................................17

DATA OF MICROPROCESSOR ...............................................................................................................................18

SEMICONDUCTORS ................................................................................................................................................. 24

WIRING DIAGRAM ....................................................................................................................................................30

PRINTED WIRING BOARD ....................................................................................................................................... 31

METHOD OF REMOVED IC ..................................................................................................................................... 36

CIRCUIT DIAGRAM ................................................................................................................................................... 37

BLOCK DIAGRAM ..................................................................................................................................................... 41

EXPLODED VIEW...................................................................................................................................................... 43

REPLACEMENT PARTS LIST ..................................................................................................................................45

This documentation is applied to rescrictions for management, export and supply to overseas based on the Wassenaar Arrangement.

SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT

November 1999

DIGITAL RECEIVER

HITACHI CONSUMER PRODUCTS (S)

KH-WS1

Check that exposed parts are acceptably insulated from the supply circuit before returning the repaired instrument to the customer.

INSTRUMENT

• Checking method

Measure the resistance value between the both poles of attachment cup (Power supply plug) and the exposed parts (Parts such as Knob, Cover, etc. where the customer is easy to touch.) and check that the resistance value is 500 kohms or more.

Insulation tester (DC 500V)

(Exposed part)

SAFETY PRECAUTIONS

The following precautions should be observed when servicing.

1. Since many parts in the unit have special safety-related characteristics, always use genuine Hitachi’s replacement parts. Especially critical parts in the power circuit block should not be replaced with other makers. Critical parts are marked with in the circuit diagram and printed wiring board.

2. Before returning a repaired unit to the customer, the service technician must thoroughly test the unit to ascertain that it is completely safe to operate without danger of electrical shock.

SPECIFICATIONS

• WS (WorldSpace digital broadcast) Section

Circuit system: Digital Receiver Broadcast method: WorldStar 1 Method Receiver frequency: L-Band (1453.384-1490.644 MHz) Input/Output terminals Antenna input terminal

Type/Impedance: F-type/50 Ω Polarization voltage: LHCP 2.5-2.2 V

RHCP 3.3-2.8 V

Max. current supply: 70 mA External terminal: 9-pin, for future expansion WS antenna (Built-in, detachable type):

WorldStar 1 Method compatible antenna Gain: over 6 dBi Dimensions: 150 x 33 x 156 mm (w x h x d)

• Radio Section

Circuit system: FM/MW/SW1/SW2 4-bands

Superheterodyne

Tuning range: FM: 87.5 - 108 MHz

MW: 522 - 1620 kHz (9 kHz steps)

520 - 1620 kHz (10 kHz steps)

SW1:2.300-7.300 MHz

Meter band: 120, 90, 75, 60, 49, 41 m

SW2:9.500-26.100 MHz

Meter band: 31, 25, 21, 19, 16, 13, 11 m

Antennas: FM/SW1/SW2: Telescopic antenna

(aerial)

MW: Built-in ferrite-core antenna

(aerial)

• General Specifications

Power supply: AC: 110-127 V/220-240 V, 50/60 Hz

DC: 6 V “D” cell or IEC R20 or equivalent x 4 (Optional) DC input jack Input voltage : DC 6 V + 30%, –10% (DC 7.8 V – 5.4 V)

Current consumption: max. 400 mA Power (mains) consumption: 5 W Audio output: 3 W (PMPO)

300 mW (DC operation, 10% THD) Speaker: 65 mm Cone/8 Ω Output/Impedance: Headphones (stereo)/

Suitable impedance: 8-100 Ω

Line out (stereo)/2.2 kΩ Battery life time: 30 hours over by using alkaline (LR20)

batteries.

12 hours over by using manganic

(R20P) batteries.

(Use HITACHI battery/Measured

method: EIAJ CP-2905A) Dimensions: 240.5 x 162.5 x 64.5 mm

240.5 x 162.5 x 93 mm (w x h x d)

(including the WS antenna and handle) Weight: 1.5 kg (without batteries),

1.9 kg (with batteries)

• Accessories

AC power cord: 1 AC plug adaptor: 1 F-type connector: 1 set (for making an extention coaxial

cable) Waterproof cover: 1 Waterproof tape: 1

NOTE:

* Specifications are subject to change without notice.

– 2 –

SERVICE POINTS

1. Removal of Back Case (Fig. 1)

(1) Remove 3 screws 1 from the back and 2 screws 2 inside the battery compartment. (2) Detach the Antenna from the Ant }. (3) Detach the connector A.

2. Removal of SATELLITE P.W.B. Board (Fig. 2)

(1) Detach all connectors B, C and D. (2) Remove 1 screw 3 from the Satellite P.W.B. Board. (3) Remove 2 screws 4 from the Satellite P.W.B. Board. (4) Release the 3 catches and slide the Satellite P.W.B. Board away.

2. Removal of TUNER P.W.B. Board (Fig. 3)

(1) Detach 5 connectors E, F, G, H and I from the Tuner P.W.B. Board. (2) Turn to the opposite side, remove 1 screw 5 from the Tuner P.W.B. Board. (3) Detach 9 catches and separate the Tuner P.W.B. Board from the sub-chassis.

3. Removal of Insulator Pad (Fig. 4)

(1) Remove 6 screws 5 from the Insulator pad.

4. Removal of Main Board (Fig. 5)

(1) Remove 4 screws 6 from the Main Board.

KH-WS1

5. Removal of Speaker (Fig. 6)

(1) Release one end of the metal pin that secures the speaker position. (2) Slide out the speaker.

6. Removal of POWER SUPPLY P.W.B. Board (Fig. 7)

(1) Remove 4 screws 7 and detach 1 connector J from the Power Supply P.W.B. board.

7. Removal of ANTENNA P.W.B. Board (Fig. 7)

(1) Remove 1 screw 9 from the Antenna P.W.B. board. (2) Gently pull the Antenna P.W.B. board outwards.

8. Removal of WS ANTENNA SUPPORT PLATE (Fig. 7)

(1) Remove the 6 screws 8 and pull the WS Antenna Support Plate away from the Back case.

– 3 –

KH-WS1

Fig. 1

Back case

Front case

Battery cover

3 Catches

Ant ·

Connector

Sub-Chassis

Connector

Fig. 2

Connector

9 Catches

Fig. 3

– 4 –

KH-WS1

Fig. 4

Fig. 5

– 5 –

KH-WS1

metal pin

Fig. 6

Fig. 7

Connector

– 6 –

KH-WS1

ADJUSTMENTS

• Adjustment points (Must adjust RADIO Part only. Adjustment on WS Part is not necessary.)

Remarks:

* After adjustment, should be fix following parts by Electro Wax.

"L201, L202, L206"

* After adjustment, do not touch the alighed components. (especially L201 and L202)

– 7 –

KH-WS1

• Adjustments

(1) Before Adjustment

1) Set the Power SW to ON.

2) Set the Radio Function.

(2) Alignment for Tuning Capacitor Voltage Range (Covering)

1) Required Instruments * Signal Generator * DC volt meter

2) Alignment Procedure * Connect a DC Volt meter to TP4 (J201)

Band Output Terminal

FM TP4

MW TP4

SW1 TP4

SW2 TP4

SG frequency & SET Tune Adjustment Reading

87.5 MHz L202 1.4 V ±0.1

108 MHz – 6 ~ 7.5 V

1) 520 kHz (10 kHz step)/522 kHz (9 kHz step) L210 1.2 V ±0.1

2) 1620 kHz CT207 7.2 V ±0.3

3) Repeat step 1-2

1) 2.3 MHz L208 1.1 V ±0.1

2) 7.3 MHz CT205 8.8 V ±0.3

3) Repeat step 1-2

1) 9.5 MHz L209 1.6 V ±0.1

2) 26.1 MHz CT206 9.0 V ±0.3

3) Repeat step 1-2

(3) Alignment for AM IF and MW, SW1, 2 Tracking

Step Item

1 AM IF

2 (1) MW Ant

(2)

(3)

3 (1) SW1 Ant

(2)

(3)

4 (1) SW2 Ant

(2)

(3)

Required Instrument & Connection

Instrument Input Output

Genescope (*1) Ferrite Ant.*2 TP1

AM signal generator F. Ant *2 TP1

400 Hz, 30% Mod.

ACVTM, oscillscope

MW: Note 2 P1 TP1

SW1,2: Note 5

P1 TP1

Remarks: Instrument Connection

*1: With a 470 µF/6.3 V capacitor to the TP2 (-) and J209/+B(+) "IC202". *2: Mean Note 2 (See page 17)

Note: AM TRACKING ERROR SPEC

6dB.

Genescope or Receiving Adjust Reading

SG Freq. Freq. (Set)

450 kHz High end Freq. T202 Max.

Note 1

600/603 kHz 600/603 kHz L206 Max.

1400/1404 kHz 1400/1404 kHz CT204

Repeat steps (1) & (2)

3.2 MHz 3.2 MHz L205 Max.

7.1 MHz 7.1 MHz CT203

Repeat steps (1) & (2)

11.65 MHz 11.65 MHz L204 Max.

21.45 MHz 21.45 MHz CT202

Repeat steps (1) & (2)

– 8 –

(4) Alignment for FM IF and FM Tracking

KH-WS1

Step Item

1IF

2(1) FM

(2)

(3)

Required Instrument & Connection

Instrument Input Output

Genescope IC201 TP1

FM signal P1 TP1

Generator

400 Hz, 22.5 kHz Dev

Note 6

Note:

1. Feed in a week signal from the Genescope. Adjust T202 for max. gain and the waveform of Fig. 1.

2. Connect AM signal generator to loop antenna,

bring near to ferrite antenna.

3. Input signal methode as follows.

Note 3

Genescope or Receiving Adjust Reading

SG Freq. Freq. (Set)

10.7 MHz High End (or T201 Max.

106.1 MHz)Freq. Note 4

90.2 MHz 90.2 MHz L201 Max.

106.1 MHz 106.1 MHz CT201

Repeat steps (1) & (2)

4. Feed in a week signal to IC201 (Note 3) from the

genescope. Use the T201 core to from the Scurve shown in the Fig. 2. Adjust the symmetry of A and B about point C for linearity.

5. SW1, SW2 dummy antenna is shown in Fig. 3.

6. FM dummy antenna is shown in Fig. 4.

R1=Rg=SG's output impedance (75 Ω), R2=75 - Rg/2

(5) Alignment for Clock Time Accuracy

Band Adjustment

FM CT301

Procedure Connection

1) Tune FM to 108 MHz

2) Connect a Freq. Counter to J308 To J308

3) Adjust CT301 to reach the frequency To Counter

118.7 MHz ±1.5 kHz

– 9 –

KH-WS1

TROUBLESHOOTING

1. System Check

Connect to AC outlet.

Check IC301 control circuit.

Does the time

and "BATT"

displays appear

on the LCD,

then they

disappear after

2 seconds?

Yes

IC303 or Q303 is

broken down.

IC303 operation

V in

V out

>3.6V

<3.6V

Can the time display

appear?

Yes

Can the power SW turn

Yes

ON?

Yes

Can the power SW turn

ON after pressing the

Reset key?

Yes

Is the oscillator circuit of

IC301 and pin

in operation?

Yes

Does the port of

IC301 pin

operate in "H"?

(+3V)

Does every port of IC301 , , , ,

and pin operate on the following?

Check IC301.

Is the voltage to the

Voltage Selector set correctly?

Yes

Is the voltage to

IC301 pin 3 V?

Yes

Is the oscillator circuit of

IC301 and pin in

operation?

Yes

Failure in the oscillator

circuit of IC302 pin for

the LCD driver or in IC302

Check "BATT"

display.

Is "BATT"

blinking on

the LCD?

Yes

Check the AC

voltage or replace

the battery in

case of battery

exhaustion.

Disconnect the power cord

and set the voltage correctly.

Check the +3 V line.

Check, the oscillator circuit

or IC301 is broken down.

Check whether IC301 pin

line is in "H" or not.

Check Q302, 307 and D318

CN302

<4.2V BATT

IC301

blinks.

Check around

IC301.

Is it broken down?

Pin No.

21 22 23 50 51 53

Is the LCD display

followed the right table?

H H L H H H

Yes

RADIO

L H H

Check and follow the flowchart for

each functions.

Proceed to each flowchart.

– 10 –

LCD display Display when the power turns ON without signal. eg) Check after resetting.

WS Function

WS SAT

AFRST - 1

Displaying "NO BEAM"

and the function

FM Function

FM 87.50MHz

2. WS section

(1) Determine whether WS circuit malfunctions or communications to control microcomputer malfunction.

LCD Display

STEREO LOCKED

KH-WS1

WS Function

Is the display of part on LCD followed on the following?

WS SAT

"SEARCH"

eg)

AFRST–1

– 1

NO BEAM (when no signal received)

At receiving

Is there any sound from speakers even though the display is correct?

Display Broadcast name (when any signal received)

Ye s

Does only the part

of Function

display appear?

LCD display is abnormal though any trouble is not found in receiving operation.

Are the operations of terminal pins for CN304 followed on the table 1 when CN304 is disconnected?

Ye s

WS S A T

(SC)

LEVEL

Failure in IC301 or CN304

Figure 1

Ye s

Problem may in

WS circuit.

Proceed to item (2).

Table 1

PG304 CN304

10 L Clock signal 58 72

11 L L L 60 75

Power Off

(STANDBY)

1L H H55

2 (L) H H H 4 4

3 Clock signal 3 3

5 Clock signal 2 2

6 L L Clock signal 1 1

7H H H77

8 L L L 57 71

9 L Clock signal 59 74

Power On

(NO BEAM)

At receive

IC101 No.

64 Pin 80 Pin

– 11 –

KH-WS1

(2) Checking and flowchart for WS circuit

Determine the display on LCD and the presence or absence of sound from speakers after turning the power ON.

Note: The terminal number of IC101is assumed 64-pin type in the flowchart. For 80-pin type, refer to tables 1 to 4 and note.

1 When no sound from speakers though any trouble is

not found in receiving and display

Start

Is any sound output from

speakers when changing the

mode into RADIO?

Ye s

Function

Is IC103 pin clocked in

at 14.725 MHz

Ye s

Are IC102 , , , pin and IC103 , , , pin

followed the table 3?

Is IC103 pin clocked out at 24.576 MHz and

clocked into IC102 pin?

Are the operations of IC103

and pin followed the

table 4?

Check the audio circuit

around IC206, IC207,

Check R155 and

around IC103 pin.

Check every port of

IC102 and IC103.

Check around IC102

pin and IC103 pin,

IC103 may malfunction.

Check around IC103,

IC103 may malfunction.

and IC210.

2 When no operation goes on

Only the part C of figure 1 or abnormal display will appear on LCD.

Start

Check whether IC301

, and pin are in "H"

or not.

Ye s

Is the oscillator circuit of

IC101 and pin

in operation?

Note : 80 Pin Type nos. and

IC101 No.

64 Pin

80 Pin

Power Off

(STANDBY)

Is any clock signal found in

IC101 and pin?

Ye s

Power On

(NO BEAM)

HHL

Check the terminals

of PG304 to IC101,

IC101 may malfunction.

Check the oscillator circuit or IC101 may

be in failure.

At receive

(reset)

Sync Pulse

Data signal

Clock signal

Data signal

(reset)

Connect to another IC

IC102

Table 2

IC103

IC102

No.

Power Off

(STANDBY)

Power On

(NO BEAM)

24 kHz

At receive

Clock signal

Data signal

Digital audio data

8 kHz

Table 3

Connect to another IC

IC103 No.

– 12 –

IC102

No.

Power Off

(STANDBY)

Power On

(NO BEAM)

At receive

(Sync puls)

Table 4

Connect to IC 101 No.

64 Pin 80 Pin

3 When the operation malfunctions after receiving operation starts

Display of part on LCD:

WS SAT

or or

Continue blinking of "SEARCH"

NO BEAM

"SEARCH"

KH-WS1

Receiving operation

"SEARCH"

etc.

Is the oscillator circuit of IC102 - and -pin in operation?

Can I2C bus line connected from IC101 - and -pin to all ICs operate? (80 pin nos. and )

Are IC101 -pin and IC102

-pin in "H"?

Is every port connected from IC101 -pin to IC102 and IC103 in "H"?

When the stations receivable with other units can not be received though the operation is proper

4 When the stations receivable with other units can not be received though the operation is proper

Start

No No

Is the synchronous pulse "H L" repeated at IC103 -pin?

Does IC103 -pin operate in "L"?

Check the circuits connected to each IC terminals, the patterns and the soldered parts, the concerned IC may malfunction.

Check around the terminals of IC103 and IC101.

Execute "SEEK" Search. Push MODE and BEAM SEEK keys.

Can IC101 -pin switch "H to L" after starting SEEK until it ends? (80 pin: )

Ye s

Does the voltage for RF101 (Tuner) -pin change from 3 V to 2.4 V when SEEK search until it ends?

Ye s

Is there voltage output between the center pin and the ground of the antenna jack on the unit when the antenna is disconnected? Does the voltage change from 3 V to 2.4 V when SEEK search until it ends?

Ye s

Check IC101.

Check IC105 and IC106.

Check the output line of IC105 and IC106, and around the terminals of RF101.

– 13 –

Check the output line of IC105 and IC106, and around the terminals of RF101.

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