Before Repair And Adjustment (Using Active Subwoofer Unit); Protection Circuitry - Panasonic SA-HT800VP Service Manual

Jig product number
RFKZ0182 (110V , 127V, 220V, 230V - 240V for for overseas domestic use)
2. Before Repair and Adjustment (Using Active
Subwoofer Unit)
Disconnect AC power, discharge Power Supply Capacitors C546 , C547, C548 & C549 through a
10 , 1W 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 120V, 60Hz in NO SIGNAL mode should be ~1000 mA .

3. Protection Circuitry

The protection circuitry may have operated if either of the following conditions is noticed:
- No sound is heard when the power is switched 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 this
unit are used.
If this occurs, follow the procedure outlines below:
1. Switch OFF the power.
2. Determine the cause of the problem and correct it.
3. Switch ON the power once again.
Note :
When the protection circuitry functions, the unit will not operate unless the power is first
switched OFF and then ON again.
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