DOWNLOAD Panasonic SA-PT70EE / SC-PT70EE Service Manual ↓ Size: 1.41 MB | Pages: 31 in PDF or view online for FREE

PSG0910008AE

Product Color:  (K)...Black Type

PAGE

PAGE

1 Notes ----------------------------------------------------------------- 3
2 Safety Precautions----------------------------------------------- 4

2.1. GENERAL GUIDELINES -------------------------------- 4
2.2. Before Repair and Adjustment ------------------------- 4
2.3. Protection Circuitry ---------------------------------------- 5
2.4. Safety Parts Information --------------------------------- 5

3 Warning -------------------------------------------------------------- 6

3.1. Prevention of Electrostatic Discharge (ESD)

to Electrostatic Sensitive (ES) Devices--------------- 6

3.2. Precaution of Laser Diode ------------------------------- 7
3.3. Service caution based on Legal restrictions -------- 8
3.4. Handling Precautions for Traverse Unit -------------- 9

4 Service Navigation --------------------------------------------- 11

4.1. Service Information -------------------------------------- 11

5 Specifications ---------------------------------------------------- 12

2

6 Schematic Diagram--------------------------------------------- 15

6.1. Main/D-Amp Circuit -------------------------------------- 15

7 Printed Circuit Board ------------------------------------------ 21

7.1. Main/D-Amp P.C.B. -------------------------------------- 21

8 Exploded View and Replacement Parts List ----------- 23

8.1. Exploded View and Mechanical Replacement

Part List ----------------------------------------------------- 23

8.2. Electrical Replacement Part List --------------------- 26

3

—This service manual contains technical information which will allow service personnel’s to understand and service this
model. 
—If the circuit is changed or modified, this information will be followed by supplement service manual to be filled with the
original service manual. 
1) The base for this model is SA-PT70GN-K. You can refer to the original service manual (Order no. PSG0910001CE). As such this
service manual does not contain the following information as below:-
Contents include for this service manual:-

• Safety Precautions
• Warning
• Service Navigation
• Specification
• Schematic Diagram

- Main/D-Amp Circuit

• Printed Circuit Board

- Main/D-Amp P.C.B.

• Exploded View and Replacement Parts List

4

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, C5702, C5703, C5704, C5706, C5708) 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, 50 Hz in NO SIGNAL mode volume minimal should be ~ 500 mA.