SA-BTT460GS, SA-BTT460PH, SA-BTT480EE, SA-BTT480GS, SC-BTT480EEK - Panasonic Audio Service Manual (repair manual). Page 4

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Be sure to disconnect the mains cord before adjusting the voltage selector as shown in Figure 1-2.
Use a minus(-) screwdriver to set the voltage selector (on the rear panel) to the voltage setting for the area in which the unit will be
used.
Note that this unit will be seriously damaged if this setting is not made correctly. (There is no voltage selector for some countries,
the correct voltage is already set.)

Figure 1-2

Disconnect AC power to discharge the AC Capacitors (C5700, C5701, C5702, C5703, C5705, C5709) through a 10 

Ω

, 10 W resis-

tor to ground.
Caution:

DO NOT SHORT-CIRCUIT DIRECTLY with a screwdriver blade, for instance, as this may destroy the solid state devices.

After repairs are completed, restore power gradually using a variac to avoid overcurrent.
Current consumption at AC 240 V, 50 Hz in NO SIGNAL mode at volume minimum should be ~ 600 mA.

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 procedures 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.