Panasonic SA-AK980, Service Manual

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1.4. Before Repair and Adjustment
Disconnect AC power to discharge unit AC Capacitors as such (C5700, C5701, C5703, C5704, C5705, C5706, C5707) 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 110V~127V / 220V~240V, 50/60 Hz in NO SIGNAL mode volume minimal should be ~ 500 mA.
1.5. 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.
1.6. Safety Parts Information
Safety Parts List:
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.
Table 1
Safety Ref. No. Part No. Part Name & Description Remarks
6 REXX0687-1 BLUE WIRE (VOLT SELECTOR-
SMPS)
13 REZX0024-1 BLACK WIRE (AC-SMPS)
14 REZX0023-1 RED WIRE (AC SMPS)
15 REXX0686-1 WHITE (VOLT SELECTOR-SMPS)
22 RGRX0070ADA REAR PANEL
41 RKMX0144A-K TOP CABINET
340 RAEX0190A-V TRAVESER ASS’Y (W/O CD SERVO)
A2 K2CQ2CA00007 AC CORD
A3 RQTX0273-M O/I BOOK (En/Sp)
DZ5701 ERZV10V511CS ZNR
S5701 K0ABCA000007 SW VOLTAGE SELECTOR
L5702 ELF22V035B LINE FILTER
T2900 G4D1A0000117 SWITCHING TRANSFORMER
T5701 ETS48AB116AC MAIN TRANSFORMER
T5751 ETS19AB256AG SUB TRANSFORMER
PC5701 B3PBA0000402 PHOTO COUPLER
PC5702 B3PBA0000402 PHOTO COUPLER
PC5720 B3PBA0000402 PHOTO COUPLER
PC5799 B3PBA0000402 PHOTO COUPLER
F1 K5D802BNA005 FUSE
FP2901 K5G4013A0001 FUSE PROTECTOR
TH5702 D4CAA2R20001 THERMISTOR
TH5860 D4CC11040013 THERMISTOR
P5701 K2AA2B000017 AC INLET
C5700 F1BAF1020020 1000pF
C5701 F0CAF334A087 0.33uF
C5703 F0C2H1040001 0.1uF 500V
C5704 F1BAF1020020 1000pF
C5705 F1BAF1020020 1000pF
C5706 F1BAF1020020 1000pF
C5707 F1BAF1020020 1000pF
PCB8 REPX0714E SMPS P.C.B.
PCB9 REPX0714E AC INLET P.C.B.
PCB10 REPX0714E VOLTAGE SELECTOR P.C.B.