Panasonic SB-WA720PP User manual

© 2004 Panasonic AVC Networks Singapore Pte.
Ltd. (RCB Registration Number: 197701580H) All
rights reserved. Unauthorized copying and
distribution is a violation of law.
SB-WA720PP
SB-WA720GCP
SB-WA520GN
Please revise the original parts list in the Service Manual to conform to the change(s) shown herein.
If new part numbers are shown, be sure to use then ordering parts.
Reason for Change
*The circled item indicates the reason. If no marking, see the Notes in the bottom column.
O1. Improve performance
2. Change of material or dimension
O3. To meet approved specification
4. Standardization
O5. Addition
O6. Deletion
7. Correction
8. Other
Interchangeability Code
**The circled item indicates the interchangeability. If no marking, see the Notes in the bottom column.
Parts Set Production
A Original
New Early Late Original or new parts may be used in early or late production set. Use original parts until exhausted, then stock new parts.
B Original
New Early Late Original parts may be used in early production sets only. New parts may be used in early or late production sets. Use original parts where possible, then stock new parts.
O C Original
New Early Late New parts only may be used in early or late production sets. Stock new parts.
D Original
New Early Late Original parts may be used in early production sets only. New parts may be used in late production sets only. Stock both original and new parts.
O E Other
Part Number
Model No. Ref.
No. Original Part No. New Part No. Notes Part Name & Descriptions Remarks
SB-WA720PP-S H500 K1YF15000004 -- 6,E 15P WIRE
HOLDER DELETE [M]
H503 -- K1YF15000004 5,C 15P WIRE
HOLDER ADD [M]
SB-WA720GCP-
SS500 R8140255 K0AFZA000005 3,C VOLTAGE SELECTOR CHANGE
[M]
SB-WA520GN-S Q511 KTC2026 B1BACG000009 1,C TRANSISTOR CHANGE
[M]
Q517 KTC2026 B1BACG000009 1,C TRANSISTOR CHANGE
[M]
[M] indicates parts that are supplied by PAVCSG.
ORDER NO. MD0407361P7
A6

File this Parts Change Notice with your copy of the Service Manual for :
Model No. SB-WA720PP-S ORDER NO. MD0401014C1
Model No. SB-WA720GCP-S ORDER NO. MD0404163C3
Model No. SB-WA520GN-S ORDER NO. MD0403116C3
T.I No. 26326 (For Factory Reference only).
2
SB-WA720PP / SB-WA720GCP / SB-WA520GN
FLE0407

ORDERNO. MD0401014C1
A6
Active Subwoofer System
SB-WA720PP
Colour
(S)...Silver Type
SPECIFICATIONS
Specification
1

Activesubwoofer
Type 1way, 1speaker system (Bass
reflex)
Speaker unit Impedance 4
Woofer 17 cm (6-3/4”) Conetype
Output sound pressure 80 dB/W(1.0m)
Frequencyrange 32 Hz-220 Hz (-16 dB)
36 Hz-190 Hz (-10 dB)
Dimensions(WxH xD) 209 x361 x463 mm
(8-7/32” x14-7/32” x18-7/32”)
Mass 11.7kg(25.8lb.)
General
Power consumption 340V
Power supply AC 120V, 60Hz
Note:
Specificationsare subject tochangewithout notice.
Mass and dimensionsare approximate.
SB-HT720P-S consistsof :
SB-FS520P-S x2, SB-FS720P-S x2and SB-PC720P-S x1
System : SC-HT720 (P) MusicCenter: SA-HT720 (P)
SatelliteSpeakers: SB-HT720 (P)
ActiveSubwoofer: SB-WA720 (PP)
System : SC-HT720 (PC) MusicCenter: SA-HT720 (PC)
SatelliteSpeakers: SB-HT720 (P)
ActiveSubwoofer: SB-WA720 (PP)
2004 PanasonicAVCNetworks Singapore Pte. Ltd. All rights
reserved. Unauthorized copying and distribution isaviolation of
law.
1. Safety Precautions
1.1. GENERALGUIDELINES
1. When servicing, observe the original lead dress. Ifashort circuit
isfound, replace all parts which have been overheated or
damaged bythe short circuit.
2

2. After servicing, see to itthat all the protective devices such as
insulation barriers, insulation papers shields are properly
installed.
3. After servicing, make the following leakage current checks to
prevent the customer from being exposed to shock hazards.
(This “SafetyPrecaution” is appliedonlyinU.S.A.)
1. Before servicing, unplug the power cord to prevent an electric
shock.
2. When replacing parts, use onlymanufacturer’srecommended
components for safety.
3. Check the condition of the power cord. Replace ifwear or damage
isevident.
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 ashock hazard.
1.1.1. LEAKAGE CURRENTCOLD CHECK
1. Unplug the AC cord and connect ajumper between the two
prongs on the plug.
2. Measure the resistance value, with an ohmmeter, between the
jumpered AC plug and each exposed metalliccabinet part on the
equipment such as screwheads, connectors, control shafts, etc.
When the exposed metallicpart has areturn path to the chassis,
the reading shouldbe between 1M and 5.2 . / When the
exposed metal does not have areturn path to the chassis, the
reading must be . Fig. 1
3

1.1.2. LEAKAGE CURRENTHOTCHECK (See Figure1.)
1. Plug the AC cord directlyinto the AC outlet. Donot use an
isolation transformer for thischeck.
2. Connect a1.5k , 10 watts resistor, inparallel with a0.15 F
capacitors, between each exposed metallicpart on the set and a
good earth ground such as awater pipe, as showninFigure 1.
3. Use an AC voltmeter, with 1000 ohms/voltor more sensitivity, to
measure the potential across the resistor.
4. Check each exposed metallicpart, and measure the voltage at
each point.
5. Reverse the AC plug inthe AC outlet and repeat each of the above
measurements.
6. The potential at anypoint shouldnot exceed 0.75 volts RMS. A
leakage current tester (Simpson Model 229 or equivalent) maybe
used to make the hot checks, leakage current must not exceed 1/2
milliamp. Incase ameasurement isoutside of the limits specified,
there isapossibilityof ashock hazard, and the equipment should
be repaired and rechecked before itisreturned to the customer.
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 leadfree solderwill have a PbF stampon the P.C.B.
Caution:
-Pb free solder has ahigher melting point that standard solder;
Typicallythe melting point is50 -70°F (30 -40°C)higher. / Please
use ahigh temperature soldering iron. Incase of the soldering
iron with temperature control, please set itto 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 completelyremove all of
the solder on the pins or solder area, and be sure to heat the
soldering points with the Pb free solder until itmelts enough.
3. Before Repair and Adjustment
4

Disconnect AC power, discharge PowerSupplyCapacitors C546, C547, C548, C549 through a
10 , 1 W resistortoground.
DO NOTSHORT-CIRCUITDIRECTLY (witha screwdriverblade, forinstance), as this may
destroysolidstate devices.
Afterrepairs are completed, restore powergraduallyusing a variac, toavoidovercurrent.
Current consumption at AC 120V, 60Hz inNO SIGNALmode shouldbe ~500 mA .
4. Protection Circuitry
The protection circuitrymayhave operatedif eitherof the following conditions are noticed:
-Nosound isheard when the power isturned on.
-Sound stops during aperformance.
The function of this circuitryis toprevent circuitrydamage if, forexample, the positive and
negative speakerconnection wires are
“shorted”, orif speakersystems withanimpedance less thanthe indicatedratedimpedance of
the amplifierare used.
If this occurs, followthe procedure outlines below:
1. Turn off the power.
2. Determine the cause of the problem and correct it.
3. Turn on the power once againafter one minute.
Note :
Whenthe protection circuitryfunctions, the unit will not operate unless the poweris first turned
off and thenon again.
5. Connection of the Speaker Cables
-Besure to connect speaker cables before connecting the AC
power supplycord.
-The load impedance of anyspeaker used with thisunitmust be 4 .
-Besure to connect the cablefrom the right speaker to the right
terminal and the cablefrom the left speaker to the left terminal.
1. Stripoff the outer covering, and twist the center conductor. Make
sure the bare ends of the wires are not unravelled. (Iftheyare,
twist them tight again.)
2. Insert the wire to the rear panel of the unitand close the lever.
5

Notes :
-To prevent damage to circuitry, never short-circuitpositive (+)and
negative (-) speaker wires.
-Besure to connect onlypositive (Copper) wires to positive (+)
terminalsand negative (Silver) wires to negative (-) terminals.
6. Disassembly Procedure
“ATTENTION SERVICER”
Some chassis components mayhave sharpedges.
Be careful whendisassembling and servicing.
1. Thissection describes procedures for checking the operation of
the major printed circuitboards and replacing the main
components.
2. For reassemblyafter operation checks or replacement, reverse
the respective procedures.
Special reassemblyprocedures are described onlywhen required.
3. Select items from the following index when checks or
replacement are required.
6

Contents
-Disassemblyof the Speaker Unit
-MainComponent Replacement Procedures
6.1. Disassemblyflow chart
The following chart is the procedure fordisassembling the casing and inside parts forinternal
inspection whencarrying out the servicing.
To assemble the unit, reverse the steps showninthe chart below.
6.2. Disassemblyof the Speaker Unitand Checking of the P.C.B.
Step1: Remove all the screws.
Step2: Remove the stand base.
7

Step3: Remove all the screws fromthe bottomof the speakerunit.
Step4: Remove the screws fromthe rearpanel’s speakerunit guide.
Step5: Remove the screws fromthe subwoofer.
8