Panasonic SA-AK22 - Safety and Precautionary Measures; Before Repair and Adjustment Safety; Protection Circuitry Function and Troubleshooting

Dimensions (W x H x D)
250 x 332 x 316 mm
Mass 8.2 kg
SYSTEM
SC-AK22 (E) Music Center: SA-AK22 (E)
Speaker: SB-AK22 (E)
SC-AK22 (EB) Music Center: SA-AK22 (EB)
Speaker: SB-AK22 (E)
SC-AK22 (EG) Music Center: SA-AK22 (EG)
Speaker: SB-AK22 (E)
Notes:
1. Specifications are subject to change without notice. Weight and
dimensions are approximate.
2. Total harmonic distortion is measured by the digital spectrum analyzer.
2001 Matsushita Electronics (S) Pte. Ltd. All rights reserved.
Unauthorized copying and distribution is a violation of law.
1. Before Repair and Adjustment
Disconnect AC power, discharge Power Supply Capacitors C536, C545, C546 through a 10 , 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 ~400mA.
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
www.freeservicemanuals.info
12/10/2014
Digitized in Heiloo, Holland