Before Repair And Adjustment - Panasonic SA-AK18 Service Manual

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1. Before Repair and Adjustment

Disconnect AC power, discharge Power Supply Capacitors C536, C545, C546 and C555 through a 10 Ω, 5W
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 should be ~200mA.
2. 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.
3. Accessories
█ SYSTEM
SC-AK18 (E)
SC-AK18 (EB)
SC-AK18 (EG)
Notes:
1. Specifiacations are subject to change without notice. Weight and
dimensions are approximate.
2. Total harmonic distortion is measured by the digital spectrum analyzer.
Remote Control Transmitter
Music Center: SA-AK18 (E)
Speaker: SB-AK18 (E)
Music Center: SA-AK18 (EB)
Speaker: SB-AK18 (E)
Music Center: SA-AK18 (EG)
Speaker: SB-AK18 (E)
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