Panasonic SBWA-930-PP Service manual

5 (1)

ORDER NO. MD0501015C1

A6

Active Subwoofer System

SB-WA930PP

Colour

(S)...Silver Type

Specification

n Active subwoofer

 

n System: SC-HT930P-S

Music Center: SA-HT930P-S

Type

1 way, 2 speaker system (Bass reflex)

 

Speaker system: SB-HT930P-S

Speaker unit(s)

Impedance 4Ω

 

Subwoofer: SB-WA930PP-S

1. Woofer

15 cm (5-7/8”) Cone type

n System: SC-HT930PC-S

Music Center: SA-HT930PC-S

2. Woofer

15 cm (5-7/8”) Cone type

 

Speaker system: SB-HT930PC-S

Output sound pressure

84 dB/W (1.0 m)

 

Subwoofer: SB-WA930PP-S

Frequency range

34 Hz-220 Hz (-16 dB)

 

 

 

38 Hz-190 Hz (-10 dB)

Note :

 

Dimensions (W x H x D)

285 mm x 402 mm x 520 mm

Specifications are subject to change without notice.

 

(11-7/32” x 15-13/16” x 20-15/32”)

Mass and dimensions are approximate.

Mass

15 kg (33.1 lbs)

 

 

n General

 

 

 

Power supply

AC 120V, 60Hz

 

 

Power consumption

390 W

 

 

SB-HT930P-S consists of :

SB-PC930P-S x 1, SB-FS930P-S x 2 and SB-FS931P-S x 2

CONTENTS

Page

Page

1 Safety Precautions

3

1.1. GENERAL GUIDELINES

3

2 Handling the Lead-free Solder

5

2.1. About lead free solder (PbF)

5

© 2005 Matsushita Electric Industrial Co. Ltd.. All rights reserved. Unauthorized copying and distribution is a violation of law.

SB-WA930PP

3

Before Repair and Adjustment

5

 

10.2. AC Inlet Circuit and Transformer Circuit

21

4

Protection Circuitry

5

 

10.3. Amplifier Circuit

22

5

Connection of the Speaker Cables

6

11

Printed Circuit Board

23

6

Disassembly Procedure

7

 

11.1. Power P.C.B.

23

 

6.1. Disassembly flow chart

7

 

11.2. AC Inlet P.C.B. and Transformer P.C.B.

25

 

6.2. Disassembly of the Speaker Unit and Checking of the

 

 

11.3. Amplifier P.C.B.

26

 

P.C.B.

9

12

Wiring Connection Diagram

27

7

Voltage Measurement and Waveform Chart

15

13

Illustration of IC , Transistors and Diodes

28

 

7.1. Voltage Measurement

15

14

Parts Location and Replacement Parts List

29

 

7.2. Waveform

16

 

14.1. Cabinet

30

8

Block Diagram

17

 

14.2. Electrical Parts List

33

9

Notes of Schematic Diagram

18

 

14.3. Packing Materials & Accessories Parts List

36

10

Schematic Diagram

19

 

14.4. Packaging

36

 

10.1. Power Circuit

19

 

 

 

2

SB-WA930PP

1 Safety Precautions

1.1.GENERAL GUIDELINES

1.When servicing, observe the original lead dress. If a short circuit is found, replace all parts which have been overheated or damaged by the short circuit.

2.After servicing, ensure that all the protective devices such as insulation barriers, insulation papers shields are properly installed.

3.After servicing, check for leakage current to prevent from being exposed to shock hazards.

(This “Safety Precaution” is applied only in U.S.A.)

1.Before servicing, unplug the power cord to prevent an electric shock.

2.When replacing parts, use only manufacturer’s recommended components for safety.

3.Check the condition of the power cord. Replace if wear or damage is evident.

4.After servicing, be sure to restore the lead dress, insulation barriers, insulation papers, shields, etc.

5.Before returning the serviced equipment to the customer, be sure to make the following insulation resistance test to prevent the customer from being exposed to a shock hazard.

1.1.1.LEAKAGE CURRENT COLD CHECK

1.Unplug the AC cord and connect a jumper between the two prongs on the plug.

2.Using an ohmmeter measure the resistance value, between the jumpered AC plug and each exposed metallic cabinet part on the equipment such as screwheads, connectors, control shafts, etc. When the exposed metallic part has a return path to the chassis, the reading should be between 1MΩ and 5.2Ω.

When the exposed metal does not have a return path to the chassis, the reading must be .

Fig. 1

1.1.2.LEAKAGE CURRENT HOT CHECK (See Figure 1.)

1.Plug the AC cord directly into the AC outlet. Do not use an isolation transformer for this check.

2.Connect a 1.5kΩ, 10 watts resistor, in parallel with a 0.15µF capacitors, between each exposed metallic part on the set and a good earth ground such as a water pipe, as shown in Figure 1.

3.Use an AC voltmeter, with 1000 ohms/volt or more sensitivity, to measure the potential across the resistor.

4.Check each exposed metallic part, and measure the voltage at each point.

5.Reverse the AC plug in the AC outlet and repeat each of the above measurements.

6.The potential at any point should not exceed 0.75 volts RMS. A leakage current tester (Simpson Model 229 or equivalent) may be used to make the hot checks, leakage current must not exceed 1/2 milliamp. Should the measurement is outside of the limits specified, there is a possibility of a shock hazard, and the equipment should be examine and rechecked before it is returned to the customer.

3

SB-WA930PP

1.1.3.Caution for fuse replacement

4

SB-WA930PP

2 Handling the Lead-free Solder

2.1.About lead free solder (PbF)

Distinction of PbF P.C.B. :

P.C.B.s (manufactured) using lead free solder will have a PbF stamp on the P.C.B.

Caution:

·Pb free solder has a higher melting point than standard solder: Typically the melting point is 50 - 70°F (30 - 40°C) higher. Please use a high temperature soldering iron. In case of the soldering iron with temperature control, please set it to 700 ± 20°F (370 ± 10°C).

·Pb free solder will tend to splash when heated too high (about 1100°F/600°C).

·When soldering or unsoldering, please completely remove all of the solder on the pins or solder area, and be sure to heat the soldering points with the Pb free solder until it melts enough.

3 Before Repair and Adjustment

Disconnect AC power, discharge Power Supply Capacitors C601 ~ C604 through a 10 Ω, 1 W resistor to ground.

DO NOT SHORT-CIRCUIT DIRECTLY (with a screwdriver blade, for instance), as this may destroy solid state devices. After repairs are completed, restore power gradually using a variac, to avoid overcurrent.

Current consumption at AC 120V, 60Hz in NO SIGNAL mode (volume at min) should be ~1000 mA .

4 Protection Circuitry

The protection circuitry may have operated if either of the following conditions are noticed:

·No sound is heard when the power is turned on.

·Sound stops during a performance.

The function of this circuitry is to prevent circuitry damage if, for example, the positive and negative speaker connection wires are “shorted”, or if speaker systems with an impedance less than the indicated rated impedance of the amplifier are used.

If this occurs, follow the procedure outlines below:

1.Turn off the power.

2.Determine the cause of the problem and correct it.

3.Turn on the power once again after one minute.

Note :

When the protection circuitry functions, the unit will not operate unless the power is first turned off and then on again.

5

SB-WA930PP

5Connection of the Speaker Cables

·Be sure to connect speaker cables before connecting the AC power supply cord.

·The load impedance of any speaker used with this unit must be 4Ω.

·Be sure to connect the cable from the right speaker to the right terminal and the cable from the left speaker to the left terminal.

1.Strip off the outer covering, and twist the center conductor. Make sure the bare ends of the wires are not unravelled. (If they are, twist them tight again.)

2.Insert the wire to the rear panel of the unit and close the lever.

6

SB-WA930PP

6 Disassembly Procedure

“ATTENTION SERVICER”

Some chassis components may have sharp edges. Be careful when disassemblin g and servicing.

1.This section describes procedures for checking the operation of the major printed circuit boards and replacing the main components.

2.For reassembly after operation checks or replacement, reverse the respective procedures. Special reassembly procedures are described only when required.

3.Select items from the following index when checks or replacement are required.

6.1.Disassembly flow chart

The following chart is the procedure for disassemblin g the casing and inside parts for internal inspection when carrying out the servicing.

To assemble the unit, reverse the steps shown in the chart below.

6.1.1.Disassembly of the Woofer Speakers

7

SB-WA930PP

6.1.2.Disassembly of the Power Amp Unit

8

SB-WA930PP

6.2.Disassembly of the Speaker Unit and Checking of the P.C.B.

6.2.1.Disassemly of the Front Panel Unit

Step 1: Slot in a steel ruler into the holes to give a gap between the Front Panel unit and the speaker cabinet assembly unit as arrow shown.

Step 3: Use the screwdriver slightly lift up the Front Panel unit as arrow shown.

Note:

Be careful with the bosses which are glued to the unit.

Steps 2: Slot a piece of wood chip in between the Front Panel unit and the steel ruler as arrow shown.

Step 4: Remove the Front Panel unit from the speaker cabinet assembly unit as arrow shown.

9

Panasonic SBWA-930-PP Service manual

SB-WA930PP

· Assembly of the Front Panel unit.

Step 1: Clean up the remaining glue at the 8 boss points and replace with the normal glue.

Step 1: Remove 4 screws from the Woofer 1.

Step 2: Remove the Woofer 1 by detaching the (+) and (-) wires.

Step 2: Replace the Front Panel unit firmly back to the

6.2.3. Disassebmly of Woofer Speaker

speaker cabinet assembly unit.

Unit 2

6.2.2. Disassebmly of Woofer Speaker

Follow Step (1) to Step (4) described in section 6.2.1.

 

Unit 1

 

Follow Step (1) to Step (4) described in section 6.2.1.

 

10

SB-WA930PP

Step 1: Remove 4 screws from the Woofer 2.

Step 2: Remove 3 screws from the rear panel.

Step 2: Remove the Woofer 2 by detaching the (+) and (-) wires.

6.2.4.Disassembly of the Power Amp Unit

Step 1: Remove 7 screws from the bottom of the speaker cabinet assembly unit.

Step 3: Slightly pull out the Power Amp unit as arrow shown.

Step 4: Disconnect the connector CN506 and pull out the entire Power Amp unit.

6.2.5. Disassembly of the Rear Panel and

Fan Unit

Follow Step (1) to Step (4) described in section 6.2.4.

11

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