DOWNLOAD Panasonic SA-VKX20EE / SC-VKX20EE Service Manual ↓ Size: 2.5 MB | Pages: 33 in PDF or view online for FREE

PSG1011004AE

Product Color: (K)...Black Type

PAGE

PAGE

1 Safety Precautions----------------------------------------------- 3

1.1. General Guidelines---------------------------------------- 3
1.2. Caution For Fuse Replacement------------------------ 3
1.3. Before Repair and Adjustment ------------------------- 3
1.4. Protection Circuitry ---------------------------------------- 4
1.5. Safety Parts Information --------------------------------- 4

2 Warning -------------------------------------------------------------- 5

2.1. Prevention of Electrostatic Discharge (ESD)

to Electrostatic Sensitive (ES) Devices--------------- 5

2.2. Precaution of Laser Diode ------------------------------- 6
2.3. Service caution based on Legal restrictions -------- 7
2.4. Handling Precautions for Traverse Unit -------------- 8

2

3 Service Navigation---------------------------------------------- 10

3.1. Service Information -------------------------------------- 10
3.2. Differences Table----------------------------------------- 11

4 Specifications ---------------------------------------------------- 12
5 Block Diagram --------------------------------------------------- 13

5.1. DVD Module ----------------------------------------------- 13

6 Schematic Diagram--------------------------------------------- 14

6.1. DVD Module Circuit-------------------------------------- 14
6.2. Main Circuit ------------------------------------------------ 18

7 Printed Circuit Board ------------------------------------------ 26

7.1. Main P.C.B. ------------------------------------------------ 26

8 Exploded View and Replacement Parts List ----------- 27

8.1. Exploded View and Mechanical Replacement

Parts List --------------------------------------------------- 27

8.2. Electrical Replacement Part List --------------------- 33

3

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 0.15

µ

F 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, C5703, C5706, C5707, C5708) through a 10 

Ω

, 10

W resistor to ground.
Caution:

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 220~240 V, 50/60 Hz in Power ON, FM Tuner, No Signal mode should be ~ 500 mA

4

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.

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

) in the Exploded View & 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.