DOWNLOAD Panasonic SA-BX500EB / SA-BX500EE / SA-BX500EG Service Manual ↓ Size: 10.2 MB | Pages: 127 in PDF or view online for FREE

 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, see to it that all the protective devices such as insulation barriers, insulation papers shields are properly

installed.

 3. After servicing, carry out the following leakage current checks to prevent the customer from being exposed to shock hazards.

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

 2. Measure the resistance value, with an ohmmeter, 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 1M

Ω

and 5.2M

Ω

.

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

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

 2. Connect a 1.5k

Ω

, 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. In case a measurement is outside of the limits
specified, there is a possibility of a shock hazard, and the equipment should be repaired and rechecked before it is returned to
the customer.

Figure 1

Disconnect AC power to discharge unit AC Capacitors as such (C5700, C5701, C5702, C5703, C5704) through a 10

Ω

, 10 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 230 V~240 V, 50 Hz in NO SIGNAL mode volume minimal should be ~ 600 mA.

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

5

“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.

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

There are special components used in this equipment which are important for safety.
These parts are marked by

in the Schematic Diagrams & Replacement Parts List. It is essential that these critical parts

should be replaced with manufacturer’s specified parts to prevent shock, fire or other hazards. Do not modify the original design
without permission of manufacturer.

Ref. No.

Part No.

Part Name & Description

Remarks

14

REXX0640-J

BLACK WIRE (SMPS-AC)

[M]

15

REXX0641-J

RED WIRE (SMPS-AC)

[M]

19

RGR0385A-A

REAR PANEL

[M]EB/EG

19

RGR0385A-B

REAR PANEL

[M] EE

30

RKM0603-K

TOP CABINET

[M]

A2

K2CQ2CA00007

AC CORD

[M] EG/EE

A2

K2CT3CA00004

AC CORD

[M] EB

PCB18

REPX0622R

SMPS P.C.B

[M] (RTL)

PCB19

REPX0622R

AC INLET P.C.B.

[M] (RTL)

DZ5701

ERZV10V511CS

ZNR

[M]

L5701

ELF15N035AN

LINE FILTER

[M]

L5702

ELF22V020E

LINE FILTER

[M]

L5703

ELF21N024E

LINE FILTER

[M]

T5701

ETS42BM1B6AC

TRANSFORMER

[M]

T5751

ETS19AB281AG

BACKUP TRANSFORMER

[M]

T7001

G4D1A0000094

SWITCHING TRANSFORMER

[M]

PC5701

B3PBA0000402

PHOTO COUPLER

[M]

PC5702

B3PBA0000402

PHOTO COUPLER

[M]

PC5720

B3PBA0000402

PHOTO COUPLER

[M]

PC5799

B3PBA0000402

PHOTO COUPLER

[M]

F1

K5D402BK0007

FUSE

[M]

IP7001

K5H7512A0010

IC PROTECTOR

[M]

TH5701

D4CAA5R10001

THERMISTOR

[M]

TH5860

D4CC11040013

THERMISTOR

[M]

P5701

K2AA2B000017

AC INLET

[M]

C5700

F1BAF1020020

1000pF

[M]

C5701

ECQU2A104MLC

0.1uF

[M]

C5702

ECQU2A104MLC

0.1uF

[M]

C5703

ECQU2A104MLC

0.1uF

[M]

C5704

F1BAF1020020

1000pF

[M]

6

For your safety, please read the following text 
carefully.

This appliance is supplied with a moulded three pin 
mains plug for your safety and convenience.
A 5-ampere fuse is fitted in this plug. 
Should the fuse need to be replaced please ensure 
that the replacement fuse has a rating of 5-ampere 
and that it is approved by ASTA or BSI to BS1362.
Check for the ASTA mark

or the BSI mark

 

on the body of the fuse.

If the plug contains a removable fuse cover you 
must ensure that it is refitted when the fuse is
replaced.
If you lose the fuse cover the plug must not be used 
until a replacement cover is obtained.
A replacement fuse cover can be purchased from 
your local dealer.

CAUTION!
IF THE FITTED MOULDED PLUG IS 
UNSUITABLE FOR THE SOCKET OUTLET IN 
YOUR HOME THEN THE FUSE SHOULD BE 
REMOVED AND THE PLUG CUT OFF AND 
DISPOSED OF SAFELY.
THERE IS A DANGER OF SEVERE 
ELECTRICAL SHOCK IF THE CUT OFF PLUG IS 
INSERTED INTO ANY 13-AMPERE SOCKET.

If a new plug is to be fitted please obser ve the 
wiring code as stated below.
If in any doubt please consult a qualified electrician.

Before use
Remove the connector cover.

How to replace the fuse
The location of the fuse differ according to the type 
of AC mains plug (figures A and B). Confirm the AC 
mains plug fitted and f ollow the instructions below.
Illustrations may differ from actual AC mains plug.

1. Open the fuse cover with a screwdriver.

2. Replace the fuse and close or attach the fuse cover.

IMPORTANT
The wires in this mains lead are coloured in 
accordance with the following code:
Blue: Neutral, Brown: Live.
As these colours may not correspond with the 
coloured markings identifying the terminals in your 
plug, proceed as follows:
The wire which is coloured Blue must be connected 
to the terminal which is marked with the letter N or 
coloured Black or Blue.
The wire which is coloured Brown must be 
connected to the terminal which is marked with the 
letter L or coloured Brown or Red.

Fuse
(5 ampere)

Fuse
(5 ampere)

Fuse cover

7

Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components commonly are called
Electrostatically Sensitive (ES) Devices. Examples of typical ES devices are integrated circuits and some field-effect transistors and
semiconductor “chip” components. The following techniques should be used to help reduce the incidence of component damage
caused by electrostatic discharge (ESD).

 1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off any ESD on your

body by touching a known earth ground. Alternatively, obtain and wear a commercially available discharging ESD wrist strap,
which should be removed for potential shock reasons prior to applying power to the unit under test.

 2. After removing an electrical assembly equipped with ES devices, place the assembly on a conductive surface such as

aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.

 3. Use only a grounded-tip soldering iron to solder or unsolder ES devices.

 4. Use only an anti-static solder removal device. Some solder removal devices not classified as “anti-static (ESD protected)” can

generate electrical charge sufficient to damage ES devices.

 5. Do not use freon-propelled chemicals. These can generate electrical charges sufficient to damage ES devices.

 6. Do not remove a replacement ES device from its protective package until immediately before you are ready to install it. (Most

replacement ES devices are packaged with leads electrically shorted together by conductive foam, aluminum foil or comparable
conductive material).

 7. Immediately before removing the protective material from the leads of a replacement ES device, touch the protective material

to the chassis or circuit assembly into which the device will be installed.

Be sure no power is applied to the chassis or circuit, and observe all other safety precautions.

 8. Minimize bodily motions when handling unpackaged replacement ES devices. (Otherwise harmless motion such as the

brushing together of your clothes fabric or the lifting of your foot from a carpeted floor can generate static electricity (ESD)
sufficient to damage an ES device).

8